Use new cinder classes from non-HA controllers

Switch out old cinder_controller class in favor of new cinder and
cinder_volume classes.
Reuse cinder_volume in Block Storage host group
Add Dell EqualLogic backend for Cinder

Based on Rajini's pull request [1].

[1] https://github.com/redhat-openstack/astapor/pull/210

Co-Authored-By: Rajini Ram <rajini_ram@dell.com>