Python 3.8 collections compatibility fixes.

Includes a new pylint blacklist plugin to prevent regressions.

lib/ansible/plugins/callback/dense.py

@@ -20,8 +20,6 @@ requirements:
 - set as stdout in configuation
 '''
 
-from collections import MutableMapping, MutableSequence
-
 HAS_OD = False
 try:
     from collections import OrderedDict
@@ -30,6 +28,7 @@ except ImportError:
     pass
 
 from ansible.module_utils.six import binary_type, text_type
+from ansible.module_utils.common._collections_compat import MutableMapping, MutableSequence
 from ansible.plugins.callback.default import CallbackModule as CallbackModule_default
 from ansible.utils.color import colorize, hostcolor