[SPARK-28284][SQL][PYTHON][TESTS] Convert and port 'join-empty-relation.sql' into UDF test base

## What changes were proposed in this pull request?

This PR adds some tests converted from `join-empty-relation.sql` to test UDFs. Please see contribution guide of this umbrella ticket - [SPARK-27921](https://issues.apache.org/jira/browse/SPARK-27921).

<details><summary>Diff comparing to 'join-empty-relation.sql'</summary>
<p>

```diff
diff --git a/sql/core/src/test/resources/sql-tests/results/join-empty-relation.sql.out b/sql/core/src/test/resources/sql-tests/results/udf/udf-join-empty-relation.sql.out
index 857073a..e79d01f 100644
--- a/sql/core/src/test/resources/sql-tests/results/join-empty-relation.sql.out
+++ b/sql/core/src/test/resources/sql-tests/results/udf/udf-join-empty-relation.sql.out
 -27,111 +27,111  struct<>

 -- !query 3
-SELECT * FROM t1 INNER JOIN empty_table
+SELECT udf(t1.a), udf(empty_table.a) FROM t1 INNER JOIN empty_table ON (udf(t1.a) = udf(udf(empty_table.a)))
 -- !query 3 schema
-struct<a:int,a:int>
+struct<CAST(udf(cast(a as string)) AS INT):int,CAST(udf(cast(a as string)) AS INT):int>
 -- !query 3 output

 -- !query 4
-SELECT * FROM t1 CROSS JOIN empty_table
+SELECT udf(t1.a), udf(udf(empty_table.a)) FROM t1 CROSS JOIN empty_table ON (udf(udf(t1.a)) = udf(empty_table.a))
 -- !query 4 schema
-struct<a:int,a:int>
+struct<CAST(udf(cast(a as string)) AS INT):int,CAST(udf(cast(cast(udf(cast(a as string)) as int) as string)) AS INT):int>
 -- !query 4 output

 -- !query 5
-SELECT * FROM t1 LEFT OUTER JOIN empty_table
+SELECT udf(udf(t1.a)), empty_table.a FROM t1 LEFT OUTER JOIN empty_table ON (udf(t1.a) = udf(empty_table.a))
 -- !query 5 schema
-struct<a:int,a:int>
+struct<CAST(udf(cast(cast(udf(cast(a as string)) as int) as string)) AS INT):int,a:int>
 -- !query 5 output
 1	NULL

 -- !query 6
-SELECT * FROM t1 RIGHT OUTER JOIN empty_table
+SELECT udf(t1.a), udf(empty_table.a) FROM t1 RIGHT OUTER JOIN empty_table ON (udf(t1.a) = udf(empty_table.a))
 -- !query 6 schema
-struct<a:int,a:int>
+struct<CAST(udf(cast(a as string)) AS INT):int,CAST(udf(cast(a as string)) AS INT):int>
 -- !query 6 output

 -- !query 7
-SELECT * FROM t1 FULL OUTER JOIN empty_table
+SELECT udf(t1.a), empty_table.a FROM t1 FULL OUTER JOIN empty_table ON (udf(t1.a) = udf(empty_table.a))
 -- !query 7 schema
-struct<a:int,a:int>
+struct<CAST(udf(cast(a as string)) AS INT):int,a:int>
 -- !query 7 output
 1	NULL

 -- !query 8
-SELECT * FROM t1 LEFT SEMI JOIN empty_table
+SELECT udf(udf(t1.a)) FROM t1 LEFT SEMI JOIN empty_table ON (udf(t1.a) = udf(udf(empty_table.a)))
 -- !query 8 schema
-struct<a:int>
+struct<CAST(udf(cast(cast(udf(cast(a as string)) as int) as string)) AS INT):int>
 -- !query 8 output

 -- !query 9
-SELECT * FROM t1 LEFT ANTI JOIN empty_table
+SELECT udf(t1.a) FROM t1 LEFT ANTI JOIN empty_table ON (udf(t1.a) = udf(empty_table.a))
 -- !query 9 schema
-struct<a:int>
+struct<CAST(udf(cast(a as string)) AS INT):int>
 -- !query 9 output
 1

 -- !query 10
-SELECT * FROM empty_table INNER JOIN t1
+SELECT udf(empty_table.a), udf(t1.a) FROM empty_table INNER JOIN t1 ON (udf(udf(empty_table.a)) = udf(t1.a))
 -- !query 10 schema
-struct<a:int,a:int>
+struct<CAST(udf(cast(a as string)) AS INT):int,CAST(udf(cast(a as string)) AS INT):int>
 -- !query 10 output

 -- !query 11
-SELECT * FROM empty_table CROSS JOIN t1
+SELECT udf(empty_table.a), udf(udf(t1.a)) FROM empty_table CROSS JOIN t1 ON (udf(empty_table.a) = udf(udf(t1.a)))
 -- !query 11 schema
-struct<a:int,a:int>
+struct<CAST(udf(cast(a as string)) AS INT):int,CAST(udf(cast(cast(udf(cast(a as string)) as int) as string)) AS INT):int>
 -- !query 11 output

 -- !query 12
-SELECT * FROM empty_table LEFT OUTER JOIN t1
+SELECT udf(udf(empty_table.a)), udf(t1.a) FROM empty_table LEFT OUTER JOIN t1 ON (udf(empty_table.a) = udf(t1.a))
 -- !query 12 schema
-struct<a:int,a:int>
+struct<CAST(udf(cast(cast(udf(cast(a as string)) as int) as string)) AS INT):int,CAST(udf(cast(a as string)) AS INT):int>
 -- !query 12 output

 -- !query 13
-SELECT * FROM empty_table RIGHT OUTER JOIN t1
+SELECT empty_table.a, udf(t1.a) FROM empty_table RIGHT OUTER JOIN t1 ON (udf(empty_table.a) = udf(t1.a))
 -- !query 13 schema
-struct<a:int,a:int>
+struct<a:int,CAST(udf(cast(a as string)) AS INT):int>
 -- !query 13 output
 NULL	1

 -- !query 14
-SELECT * FROM empty_table FULL OUTER JOIN t1
+SELECT empty_table.a, udf(udf(t1.a)) FROM empty_table FULL OUTER JOIN t1 ON (udf(empty_table.a) = udf(t1.a))
 -- !query 14 schema
-struct<a:int,a:int>
+struct<a:int,CAST(udf(cast(cast(udf(cast(a as string)) as int) as string)) AS INT):int>
 -- !query 14 output
 NULL	1

 -- !query 15
-SELECT * FROM empty_table LEFT SEMI JOIN t1
+SELECT udf(udf(empty_table.a)) FROM empty_table LEFT SEMI JOIN t1 ON (udf(empty_table.a) = udf(udf(t1.a)))
 -- !query 15 schema
-struct<a:int>
+struct<CAST(udf(cast(cast(udf(cast(a as string)) as int) as string)) AS INT):int>
 -- !query 15 output

 -- !query 16
-SELECT * FROM empty_table LEFT ANTI JOIN t1
+SELECT empty_table.a FROM empty_table LEFT ANTI JOIN t1 ON (udf(empty_table.a) = udf(t1.a))
 -- !query 16 schema
 struct<a:int>
 -- !query 16 output
 -139,56 +139,56  struct<a:int>

 -- !query 17
-SELECT * FROM empty_table INNER JOIN empty_table
+SELECT udf(empty_table.a) FROM empty_table INNER JOIN empty_table AS empty_table2 ON (udf(empty_table.a) = udf(udf(empty_table2.a)))
 -- !query 17 schema
-struct<a:int,a:int>
+struct<CAST(udf(cast(a as string)) AS INT):int>
 -- !query 17 output

 -- !query 18
-SELECT * FROM empty_table CROSS JOIN empty_table
+SELECT udf(udf(empty_table.a)) FROM empty_table CROSS JOIN empty_table AS empty_table2 ON (udf(udf(empty_table.a)) = udf(empty_table2.a))
 -- !query 18 schema
-struct<a:int,a:int>
+struct<CAST(udf(cast(cast(udf(cast(a as string)) as int) as string)) AS INT):int>
 -- !query 18 output

 -- !query 19
-SELECT * FROM empty_table LEFT OUTER JOIN empty_table
+SELECT udf(empty_table.a) FROM empty_table LEFT OUTER JOIN empty_table AS empty_table2 ON (udf(empty_table.a) = udf(empty_table2.a))
 -- !query 19 schema
-struct<a:int,a:int>
+struct<CAST(udf(cast(a as string)) AS INT):int>
 -- !query 19 output

 -- !query 20
-SELECT * FROM empty_table RIGHT OUTER JOIN empty_table
+SELECT udf(udf(empty_table.a)) FROM empty_table RIGHT OUTER JOIN empty_table AS empty_table2 ON (udf(empty_table.a) = udf(udf(empty_table2.a)))
 -- !query 20 schema
-struct<a:int,a:int>
+struct<CAST(udf(cast(cast(udf(cast(a as string)) as int) as string)) AS INT):int>
 -- !query 20 output

 -- !query 21
-SELECT * FROM empty_table FULL OUTER JOIN empty_table
+SELECT udf(empty_table.a) FROM empty_table FULL OUTER JOIN empty_table AS empty_table2 ON (udf(empty_table.a) = udf(empty_table2.a))
 -- !query 21 schema
-struct<a:int,a:int>
+struct<CAST(udf(cast(a as string)) AS INT):int>
 -- !query 21 output

 -- !query 22
-SELECT * FROM empty_table LEFT SEMI JOIN empty_table
+SELECT udf(udf(empty_table.a)) FROM empty_table LEFT SEMI JOIN empty_table AS empty_table2 ON (udf(empty_table.a) = udf(empty_table2.a))
 -- !query 22 schema
-struct<a:int>
+struct<CAST(udf(cast(cast(udf(cast(a as string)) as int) as string)) AS INT):int>
 -- !query 22 output

 -- !query 23
-SELECT * FROM empty_table LEFT ANTI JOIN empty_table
+SELECT udf(empty_table.a) FROM empty_table LEFT ANTI JOIN empty_table AS empty_table2 ON (udf(empty_table.a) = udf(empty_table2.a))
 -- !query 23 schema
-struct<a:int>
+struct<CAST(udf(cast(a as string)) AS INT):int>
 -- !query 23 output

```
</p>
</details>

## How was this patch tested?

Tested as guided in [SPARK-27921](https://issues.apache.org/jira/browse/SPARK-27921).

Closes apache#25127 from imback82/join-empty-relation-sql.

Authored-by: Terry Kim <[email protected]>
Signed-off-by: HyukjinKwon <[email protected]>

Author: imback82

sql/core/src/test/resources/sql-tests/inputs/udf/udf-join-empty-relation.sql

@@ -0,0 +1,35 @@
+-- List of configuration the test suite is run against:
+--SET spark.sql.autoBroadcastJoinThreshold=10485760
+--SET spark.sql.autoBroadcastJoinThreshold=-1,spark.sql.join.preferSortMergeJoin=true
+--SET spark.sql.autoBroadcastJoinThreshold=-1,spark.sql.join.preferSortMergeJoin=false
+
+-- This test file was converted from join-empty-relation.sql.
+
+CREATE TEMPORARY VIEW t1 AS SELECT * FROM VALUES (1) AS GROUPING(a);
+CREATE TEMPORARY VIEW t2 AS SELECT * FROM VALUES (1) AS GROUPING(a);
+
+CREATE TEMPORARY VIEW empty_table as SELECT a FROM t2 WHERE false;
+
+SELECT udf(t1.a), udf(empty_table.a) FROM t1 INNER JOIN empty_table ON (udf(t1.a) = udf(udf(empty_table.a)));
+SELECT udf(t1.a), udf(udf(empty_table.a)) FROM t1 CROSS JOIN empty_table ON (udf(udf(t1.a)) = udf(empty_table.a));
+SELECT udf(udf(t1.a)), empty_table.a FROM t1 LEFT OUTER JOIN empty_table ON (udf(t1.a) = udf(empty_table.a));
+SELECT udf(t1.a), udf(empty_table.a) FROM t1 RIGHT OUTER JOIN empty_table ON (udf(t1.a) = udf(empty_table.a));
+SELECT udf(t1.a), empty_table.a FROM t1 FULL OUTER JOIN empty_table ON (udf(t1.a) = udf(empty_table.a));
+SELECT udf(udf(t1.a)) FROM t1 LEFT SEMI JOIN empty_table ON (udf(t1.a) = udf(udf(empty_table.a)));
+SELECT udf(t1.a) FROM t1 LEFT ANTI JOIN empty_table ON (udf(t1.a) = udf(empty_table.a));
+
+SELECT udf(empty_table.a), udf(t1.a) FROM empty_table INNER JOIN t1 ON (udf(udf(empty_table.a)) = udf(t1.a));
+SELECT udf(empty_table.a), udf(udf(t1.a)) FROM empty_table CROSS JOIN t1 ON (udf(empty_table.a) = udf(udf(t1.a)));
+SELECT udf(udf(empty_table.a)), udf(t1.a) FROM empty_table LEFT OUTER JOIN t1 ON (udf(empty_table.a) = udf(t1.a));
+SELECT empty_table.a, udf(t1.a) FROM empty_table RIGHT OUTER JOIN t1 ON (udf(empty_table.a) = udf(t1.a));
+SELECT empty_table.a, udf(udf(t1.a)) FROM empty_table FULL OUTER JOIN t1 ON (udf(empty_table.a) = udf(t1.a));
+SELECT udf(udf(empty_table.a)) FROM empty_table LEFT SEMI JOIN t1 ON (udf(empty_table.a) = udf(udf(t1.a)));
+SELECT empty_table.a FROM empty_table LEFT ANTI JOIN t1 ON (udf(empty_table.a) = udf(t1.a));
+
+SELECT udf(empty_table.a) FROM empty_table INNER JOIN empty_table AS empty_table2 ON (udf(empty_table.a) = udf(udf(empty_table2.a)));
+SELECT udf(udf(empty_table.a)) FROM empty_table CROSS JOIN empty_table AS empty_table2 ON (udf(udf(empty_table.a)) = udf(empty_table2.a));
+SELECT udf(empty_table.a) FROM empty_table LEFT OUTER JOIN empty_table AS empty_table2 ON (udf(empty_table.a) = udf(empty_table2.a));
+SELECT udf(udf(empty_table.a)) FROM empty_table RIGHT OUTER JOIN empty_table AS empty_table2 ON (udf(empty_table.a) = udf(udf(empty_table2.a)));
+SELECT udf(empty_table.a) FROM empty_table FULL OUTER JOIN empty_table AS empty_table2 ON (udf(empty_table.a) = udf(empty_table2.a));
+SELECT udf(udf(empty_table.a)) FROM empty_table LEFT SEMI JOIN empty_table AS empty_table2 ON (udf(empty_table.a) = udf(empty_table2.a));
+SELECT udf(empty_table.a) FROM empty_table LEFT ANTI JOIN empty_table AS empty_table2 ON (udf(empty_table.a) = udf(empty_table2.a));

sql/core/src/test/resources/sql-tests/results/udf/udf-join-empty-relation.sql.out

@@ -0,0 +1,194 @@
+-- Automatically generated by SQLQueryTestSuite
+-- Number of queries: 24
+
+
+-- !query 0
+CREATE TEMPORARY VIEW t1 AS SELECT * FROM VALUES (1) AS GROUPING(a)
+-- !query 0 schema
+struct<>
+-- !query 0 output
+
+
+
+-- !query 1
+CREATE TEMPORARY VIEW t2 AS SELECT * FROM VALUES (1) AS GROUPING(a)
+-- !query 1 schema
+struct<>
+-- !query 1 output
+
+
+
+-- !query 2
+CREATE TEMPORARY VIEW empty_table as SELECT a FROM t2 WHERE false
+-- !query 2 schema
+struct<>
+-- !query 2 output
+
+
+
+-- !query 3
+SELECT udf(t1.a), udf(empty_table.a) FROM t1 INNER JOIN empty_table ON (udf(t1.a) = udf(udf(empty_table.a)))
+-- !query 3 schema
+struct<CAST(udf(cast(a as string)) AS INT):int,CAST(udf(cast(a as string)) AS INT):int>
+-- !query 3 output
+
+
+
+-- !query 4
+SELECT udf(t1.a), udf(udf(empty_table.a)) FROM t1 CROSS JOIN empty_table ON (udf(udf(t1.a)) = udf(empty_table.a))
+-- !query 4 schema
+struct<CAST(udf(cast(a as string)) AS INT):int,CAST(udf(cast(cast(udf(cast(a as string)) as int) as string)) AS INT):int>
+-- !query 4 output
+
+
+
+-- !query 5
+SELECT udf(udf(t1.a)), empty_table.a FROM t1 LEFT OUTER JOIN empty_table ON (udf(t1.a) = udf(empty_table.a))
+-- !query 5 schema
+struct<CAST(udf(cast(cast(udf(cast(a as string)) as int) as string)) AS INT):int,a:int>
+-- !query 5 output
+1	NULL
+
+
+-- !query 6
+SELECT udf(t1.a), udf(empty_table.a) FROM t1 RIGHT OUTER JOIN empty_table ON (udf(t1.a) = udf(empty_table.a))
+-- !query 6 schema
+struct<CAST(udf(cast(a as string)) AS INT):int,CAST(udf(cast(a as string)) AS INT):int>
+-- !query 6 output
+
+
+
+-- !query 7
+SELECT udf(t1.a), empty_table.a FROM t1 FULL OUTER JOIN empty_table ON (udf(t1.a) = udf(empty_table.a))
+-- !query 7 schema
+struct<CAST(udf(cast(a as string)) AS INT):int,a:int>
+-- !query 7 output
+1	NULL
+
+
+-- !query 8
+SELECT udf(udf(t1.a)) FROM t1 LEFT SEMI JOIN empty_table ON (udf(t1.a) = udf(udf(empty_table.a)))
+-- !query 8 schema
+struct<CAST(udf(cast(cast(udf(cast(a as string)) as int) as string)) AS INT):int>
+-- !query 8 output
+
+
+
+-- !query 9
+SELECT udf(t1.a) FROM t1 LEFT ANTI JOIN empty_table ON (udf(t1.a) = udf(empty_table.a))
+-- !query 9 schema
+struct<CAST(udf(cast(a as string)) AS INT):int>
+-- !query 9 output
+1
+
+
+-- !query 10
+SELECT udf(empty_table.a), udf(t1.a) FROM empty_table INNER JOIN t1 ON (udf(udf(empty_table.a)) = udf(t1.a))
+-- !query 10 schema
+struct<CAST(udf(cast(a as string)) AS INT):int,CAST(udf(cast(a as string)) AS INT):int>
+-- !query 10 output
+
+
+
+-- !query 11
+SELECT udf(empty_table.a), udf(udf(t1.a)) FROM empty_table CROSS JOIN t1 ON (udf(empty_table.a) = udf(udf(t1.a)))
+-- !query 11 schema
+struct<CAST(udf(cast(a as string)) AS INT):int,CAST(udf(cast(cast(udf(cast(a as string)) as int) as string)) AS INT):int>
+-- !query 11 output
+
+
+
+-- !query 12
+SELECT udf(udf(empty_table.a)), udf(t1.a) FROM empty_table LEFT OUTER JOIN t1 ON (udf(empty_table.a) = udf(t1.a))
+-- !query 12 schema
+struct<CAST(udf(cast(cast(udf(cast(a as string)) as int) as string)) AS INT):int,CAST(udf(cast(a as string)) AS INT):int>
+-- !query 12 output
+
+
+
+-- !query 13
+SELECT empty_table.a, udf(t1.a) FROM empty_table RIGHT OUTER JOIN t1 ON (udf(empty_table.a) = udf(t1.a))
+-- !query 13 schema
+struct<a:int,CAST(udf(cast(a as string)) AS INT):int>
+-- !query 13 output
+NULL	1
+
+
+-- !query 14
+SELECT empty_table.a, udf(udf(t1.a)) FROM empty_table FULL OUTER JOIN t1 ON (udf(empty_table.a) = udf(t1.a))
+-- !query 14 schema
+struct<a:int,CAST(udf(cast(cast(udf(cast(a as string)) as int) as string)) AS INT):int>
+-- !query 14 output
+NULL	1
+
+
+-- !query 15
+SELECT udf(udf(empty_table.a)) FROM empty_table LEFT SEMI JOIN t1 ON (udf(empty_table.a) = udf(udf(t1.a)))
+-- !query 15 schema
+struct<CAST(udf(cast(cast(udf(cast(a as string)) as int) as string)) AS INT):int>
+-- !query 15 output
+
+
+
+-- !query 16
+SELECT empty_table.a FROM empty_table LEFT ANTI JOIN t1 ON (udf(empty_table.a) = udf(t1.a))
+-- !query 16 schema
+struct<a:int>
+-- !query 16 output
+
+
+
+-- !query 17
+SELECT udf(empty_table.a) FROM empty_table INNER JOIN empty_table AS empty_table2 ON (udf(empty_table.a) = udf(udf(empty_table2.a)))
+-- !query 17 schema
+struct<CAST(udf(cast(a as string)) AS INT):int>
+-- !query 17 output
+
+
+
+-- !query 18
+SELECT udf(udf(empty_table.a)) FROM empty_table CROSS JOIN empty_table AS empty_table2 ON (udf(udf(empty_table.a)) = udf(empty_table2.a))
+-- !query 18 schema
+struct<CAST(udf(cast(cast(udf(cast(a as string)) as int) as string)) AS INT):int>
+-- !query 18 output
+
+
+
+-- !query 19
+SELECT udf(empty_table.a) FROM empty_table LEFT OUTER JOIN empty_table AS empty_table2 ON (udf(empty_table.a) = udf(empty_table2.a))
+-- !query 19 schema
+struct<CAST(udf(cast(a as string)) AS INT):int>
+-- !query 19 output
+
+
+
+-- !query 20
+SELECT udf(udf(empty_table.a)) FROM empty_table RIGHT OUTER JOIN empty_table AS empty_table2 ON (udf(empty_table.a) = udf(udf(empty_table2.a)))
+-- !query 20 schema
+struct<CAST(udf(cast(cast(udf(cast(a as string)) as int) as string)) AS INT):int>
+-- !query 20 output
+
+
+
+-- !query 21
+SELECT udf(empty_table.a) FROM empty_table FULL OUTER JOIN empty_table AS empty_table2 ON (udf(empty_table.a) = udf(empty_table2.a))
+-- !query 21 schema
+struct<CAST(udf(cast(a as string)) AS INT):int>
+-- !query 21 output
+
+
+
+-- !query 22
+SELECT udf(udf(empty_table.a)) FROM empty_table LEFT SEMI JOIN empty_table AS empty_table2 ON (udf(empty_table.a) = udf(empty_table2.a))
+-- !query 22 schema
+struct<CAST(udf(cast(cast(udf(cast(a as string)) as int) as string)) AS INT):int>
+-- !query 22 output
+
+
+
+-- !query 23
+SELECT udf(empty_table.a) FROM empty_table LEFT ANTI JOIN empty_table AS empty_table2 ON (udf(empty_table.a) = udf(empty_table2.a))
+-- !query 23 schema
+struct<CAST(udf(cast(a as string)) AS INT):int>
+-- !query 23 output
+