update and consolidate errors related to iterators and yield (#41632)

* Add stubs for new warnings and errors.

* Combine existing errors

* fix build warnings

* Edit pass

* build warnings

Author: BillWagner

.openpublishing.redirection.csharp.json

@@ -400,17 +400,21 @@
             "redirect_url": "/dotnet/csharp/language-reference/compiler-messages/array-declaration-errors"
         },
         {
-            "source_path_from_root": "/docs/csharp/language-reference/compiler-messages/cs7000.md",
-            "redirect_url": "/dotnet/csharp/language-reference/compiler-messages/using-directive-errors"
+            "source_path_from_root": "/docs/csharp/language-reference/compiler-messages/cs4013.md",
+            "redirect_url": "/dotnet/csharp/language-reference/compiler-messages/iterator-yield"
         },
         {
-            "source_path_from_root": "/docs/csharp/language-reference/compiler-messages/cs8400.md",
-            "redirect_url": "/dotnet/csharp/language-reference/compiler-messages/feature-version-errors"
+            "source_path_from_root": "/docs/csharp/language-reference/compiler-messages/cs7000.md",
+            "redirect_url": "/dotnet/csharp/language-reference/compiler-messages/using-directive-errors"
         },
         {
             "source_path_from_root": "/docs/csharp/language-reference/compiler-messages/cs8153.md",
             "redirect_url": "/dotnet/csharp/language-reference/compiler-messages/lambda-expression-errors#conversion-to-expression-trees"
         },
+        {
+            "source_path_from_root": "/docs/csharp/language-reference/compiler-messages/cs8154.md",
+            "redirect_url": "/dotnet/csharp/language-reference/compiler-messages/iterator-yield"
+        },
         {
             "source_path_from_root": "/docs/csharp/language-reference/compiler-messages/cs8155.md",
             "redirect_url": "/dotnet/csharp/language-reference/compiler-messages/lambda-expression-errors#conversion-to-expression-trees"
@@ -435,6 +439,10 @@
             "source_path_from_root": "/docs/csharp/language-reference/compiler-messages/cs8175.md",
             "redirect_url": "/dotnet/csharp/language-reference/compiler-messages/lambda-expression-errors#syntax-limitations-in-lambda-expressions"
         },
+        {
+            "source_path_from_root": "/docs/csharp/language-reference/compiler-messages/cs8176.md",
+            "redirect_url": "/dotnet/csharp/language-reference/compiler-messages/iterator-yield"
+        },
         {
             "source_path_from_root": "/docs/csharp/language-reference/compiler-messages/cs8373.md",
             "redirect_url": "/dotnet/csharp/language-reference/compiler-messages/ref-modifiers-errors"
@@ -443,6 +451,10 @@
             "source_path_from_root": "/docs/csharp/language-reference/compiler-messages/cs8374.md",
             "redirect_url": "/dotnet/csharp/language-reference/compiler-messages/ref-modifiers-errors"
         },
+        {
+            "source_path_from_root": "/docs/csharp/language-reference/compiler-messages/cs8400.md",
+            "redirect_url": "/dotnet/csharp/language-reference/compiler-messages/feature-version-errors"
+        },
         {
             "source_path_from_root": "/docs/csharp/language-reference/compiler-messages/cs8401.md",
             "redirect_url": "/dotnet/csharp/language-reference/compiler-messages/feature-version-errors"
@@ -1668,18 +1680,50 @@
             "source_path_from_root": "/docs/csharp/misc/cs1621.md",
             "redirect_url": "/dotnet/csharp/language-reference/compiler-messages/lambda-expression-errors#syntax-limitations-in-lambda-expressions"
         },
+        {
+            "source_path_from_root": "/docs/csharp/misc/cs1622.md",
+            "redirect_url": "/dotnet/csharp/language-reference/compiler-messages/iterator-yield"
+        },
         {
             "source_path_from_root": "/docs/csharp/misc/cs1623.md",
             "redirect_url": "/dotnet/csharp/language-reference/compiler-messages/ref-modifiers-errors"
         },
+        {
+            "source_path_from_root": "/docs/csharp/misc/cs1624.md",
+            "redirect_url": "/dotnet/csharp/language-reference/compiler-messages/iterator-yield"
+        },
+        {
+            "source_path_from_root": "/docs/csharp/misc/cs1625.md",
+            "redirect_url": "/dotnet/csharp/language-reference/compiler-messages/iterator-yield"
+        },
+        {
+            "source_path_from_root": "/docs/csharp/misc/cs1626.md",
+            "redirect_url": "/dotnet/csharp/language-reference/compiler-messages/iterator-yield"
+        },
+        {
+            "source_path_from_root": "/docs/csharp/misc/cs1627.md",
+            "redirect_url": "/dotnet/csharp/language-reference/compiler-messages/iterator-yield"
+        },
         {
             "source_path_from_root": "/docs/csharp/misc/cs1628.md",
             "redirect_url": "/dotnet/csharp/language-reference/compiler-messages/lambda-expression-errors#syntax-limitations-in-lambda-expressions"
         },
+        {
+            "source_path_from_root": "/docs/csharp/misc/cs1629.md",
+            "redirect_url": "/dotnet/csharp/language-reference/compiler-messages/iterator-yield"
+        },
+        {
+            "source_path_from_root": "/docs/csharp/misc/cs1631.md",
+            "redirect_url": "/dotnet/csharp/language-reference/compiler-messages/iterator-yield"
+        },
         {
             "source_path_from_root": "/docs/csharp/misc/cs1632.md",
             "redirect_url": "/dotnet/csharp/language-reference/compiler-messages/lambda-expression-errors#syntax-limitations-in-lambda-expressions"
         },
+        {
+            "source_path_from_root": "/docs/csharp/misc/cs1637.md",
+            "redirect_url": "/dotnet/csharp/language-reference/compiler-messages/iterator-yield"
+        },
         {
             "source_path_from_root": "/docs/csharp/misc/cs1649.md",
             "redirect_url": "/dotnet/csharp/language-reference/compiler-messages/ref-modifiers-errors"