update code to python3 (#10903)

* update code to python3

* add changelog frag

* rollback adjustment for plugins/lookup/lmdb_kv.py

* accept PR suggestion for plugins/module_utils/utm_utils.py

* accept PR suggestion for plugins/module_utils/vexata.py

* Apply suggestions from code review

* Update changelogs/fragments/10903-2to3.yml

* Update changelogs/fragments/10903-2to3.yml

plugins/cache/pickle.py

@@ -42,10 +42,7 @@ options:
     type: float
 """
 
-try:
-    import cPickle as pickle
-except ImportError:
-    import pickle
+import pickle
 
 from ansible.plugins.cache import BaseFileCacheModule