[stable-9] Unit tests: replace mock and compat with code from community.internal_test_tools (#9923)

* Unit tests: replace mock and compat with code from community.internal_test_tools (#9921)

* Replace compat with equivalent from community.internal_test_tools.

* Replace mock with equivalent from community.internal_test_tools.

* Remove ignore.txt entries.

* Add test that's no longer present in later versions.

tests/unit/plugins/module_utils/test_ocapi_utils.py

@@ -11,7 +11,7 @@ import re
 import shutil
 import tempfile
 
-from ansible_collections.community.general.tests.unit.compat import unittest
+from ansible_collections.community.internal_test_tools.tests.unit.compat import unittest
 from ansible_collections.community.general.plugins.module_utils.ocapi_utils import OcapiUtils