Rename CertManager to CertActionClient

ActionClient as in the "client" in a command pattern.
Rename CertManager to ActionClient

Action client, as the client part of a command pattern.
In this case used to trigger actions.
rename certmgr.py to action_client
certlib.DataLib -> certlib.BaseActionInvoker

name based on "command" pattern.
entcertlib.EntCertLib -> EntCertActionInvoker
FactLib -> FactsActionInvoker
FactActionReport -> FactsActionReport
FactAction -> FactsActionCommand
healiblib.HealingLib -> HealingActionInvoker
IdentityCertLib -> IdentityCertActionInvoker
InstalledProductsLib -> InstalledProductsActionInvoker

InstalledProductsAction ->
  InstalledProductsActionCommand
repolib.RepoLib -> RepoActionInvoker
repolib.RepoUpdateAction ->RepoUpdateActionCommand
TestDataLib -> TestBaseActionInvoker