Manage volume pools for backends

Problem statement:
In case of one volume driver backend can have many volume pools. Openstack cinder has lack option for managing how the volume will be placed on which pool. Currently, cinder will determine cinder pool mostly relying on the stats of each pool (eg. utilization, oversubscription)

Proposal:
Can set properties for the cinder pool and cinder will use these options in the volume-creating progress.
 E.g.
- Can set priority pool
- Can enable/disable pool
...