Datastores improvements

List of improvements:
- added default_version field in datastore show output
- admin can list deactivated versions too
- admin can see extanded info about datastore version (image_id, packages)
- add possibility to retrive version by uuid (without specified datastore)

Implements: blueprint datastore-type-version-followon

Change-Id: I9b0c3547fb6a881a01db9e6e3d8d72077bc5ee29
Merge "Datastores improvements"