mgr/ansible: Adapt code to use DriveGroupSpec and OrchestratorClientMixin
Apart of this two major changes, and due the long time this PR has been opened, other minor modifications coming from the orchestrators world has been merged.
Not solved yet the discussion around <osd add/rm vs osd create/remove>. Once we have a a common code base we can decide what names we should use and what implementation is the more adequate.
Signed-off-by: Juan Miguel Olmo Martínez <jolmomar@redhat.com>