[3.14] gh-141004: Document built-in iterator types in the C API (GH-141006) (GH-141134)

gh-141004: Document built-in iterator types in the C API (GH-141006)

Adds documentation for each of the following:

- PyEnum_Type
- PyFilter_Type
- PyMap_Type
- PyReversed_Type
- PyZip_Type

In addition, PyRange_Type and PyRange_Check are also documented.
(cherry picked from commit 1697cb5710f526d38816bb00ca3dcd4434e5e773)

Co-authored-by: Peter Bierma <zintensitydev@gmail.com>