Move real/complex interval fields to new coercion model

[jdemeyer]

Also fix the following:

sage: NF.<a> = QuadraticField(-2)
sage: CIF(a)
...
ValueError: can not convert complex algebraic number to real interval

We also deal with Python 3 compatibility regarding int/long and bytes/unicode.

Depends on #24423

CC: @tscrim

Component: coercion

Author: Jeroen Demeyer

Branch/Commit: 9ac1612

Reviewer: Travis Scrimshaw

Issue created by migration from https://trac.sagemath.org/ticket/24371

[jdemeyer]

Branch: u/jdemeyer/move_real_complex_interval_fields_to_new_coercion_model

[sagetrac-git]

Commit: db4611a

[sagetrac-git]

Branch pushed to git repo; I updated commit sha1. This was a forced push. New commits:

375e40f	Map._extra_slots(): do not pass dict
db4611a	Move real/complex interval fields to new coercion model

[jdemeyer]

Author: Jeroen Demeyer

[jdemeyer]

Dependencies: #24372

[sagetrac-git]

Branch pushed to git repo; I updated commit sha1. This was a forced push. New commits:

549bd7d

Move real/complex interval fields to new coercion model

[sagetrac-git]

Changed commit from db4611a to 549bd7d

[sagetrac-git]

Changed commit from 549bd7d to fe4c823

[sagetrac-git]

Branch pushed to git repo; I updated commit sha1. This was a forced push. New commits:

fe4c823

Move real/complex interval fields to new coercion model

[jdemeyer]

Description changed:

--- 
+++ 
@@ -1 +1,25 @@
+Also fix this:
 
+```
+sage: CC.one() + CIF.one()
+---------------------------------------------------------------------------
+TypeError                                 Traceback (most recent call last)
+<ipython-input-20-661099892a1e> in <module>()
+----> 1 CC.one() + CIF.one()
+
+/usr/local/src/sage-git/src/sage/structure/element.pyx in sage.structure.element.Element.__add__ (build/cythonized/sage/structure/element.c:10884)()
+   1240         # Left and right are Sage elements => use coercion model
+   1241         if BOTH_ARE_ELEMENT(cl):
+-> 1242             return coercion_model.bin_op(left, right, add)
+   1243 
+   1244         try:
+
+/usr/local/src/sage-git/src/sage/structure/coerce.pyx in sage.structure.coerce.CoercionModel_cache_maps.bin_op (build/cythonized/sage/structure/coerce.c:10736)()
+   1137         # We should really include the underlying error.
+   1138         # This causes so much headache.
+-> 1139         raise bin_op_exception(op, x, y)
+   1140 
+   1141     cpdef canonical_coercion(self, x, y):
+
+TypeError: unsupported operand parent(s) for +: 'Complex Field with 53 bits of precision' and 'Complex Interval Field with 53 bits of precision'
+```

[sagetrac-git]

Branch pushed to git repo; I updated commit sha1. This was a forced push. New commits:

2cee3a4

Move real/complex interval fields to new coercion model