Sharing codes for volumes list tests

1. merge the common tests between v1 and v2, and set its
   default value for v2.
2. make volumes v1 list tests inherits common tests
3. leave volumes v2 specific tests in direcotry 'tempest/api/volume/v2'
4. delete BaseVolumeV2Test

Partially implements: blueprint cinder-v2-api-tests

Change-Id: I7cecbde9543c441a2f3478941f85625755aabf7f
3 files changed