[3.11] gh-106016: Add Lib/test/test_module/ directory (GH-108293) (#108304)

gh-106016: Add Lib/test/test_module/ directory (GH-108293)

* Move Python scripts related to test_module to this new directory:
  good_getattr.py and bad_getattrX.py scripts.
* Move Lib/test/test_module.py to Lib/test/test_module/__init__.py.
(cherry picked from commit adfc118fdab66882599e01a84c22bd897055f3f1)

Co-authored-by: Victor Stinner <vstinner@python.org>