Refactor nova.volume.cinder.API to reduce roundtrips with Cinder

Make cinder.API methods accept volume_id instead of the whole volume object.
This will remove redundant roundtrip to get the volume before
passing it to other methods as in fact they only need the id.

Fixes bug 1172297

Change-Id: I5e7f944c1c29b2f211ece2ef86c0959c81e806df
Merge "Refactor nova.volume.cinder.API to reduce roundtrips with Cinder"