Enable VolumeGroup snapshot support for OCP.

VolumeGroup Snapshot is a key requirement for OpenShift Backup and DR capabilities.  ODF currently offers the DR solution for OCP but can only protect Applications that are limited to single volume.  This severely limits the class of Applications that can be supported for DR.  Same with Backup.  Almost all business critical Applications are multi-volume based and in order to either provide a backup protection or replication DR protection it is critical that there is a consistent snapshot be created over all these volumes that belong to an Application.  Hence the need for VolumeGroup Snapshot.  Once this feature is supported by OCP Storage, CSI drivers for Ceph RBD and CephFS can be extended to provide the 'Consistency Group' protection capability for Backup & DR by ODF and all our Backup partners.

This is a must have requirement for these Key Applications, which have the highest customer impact:

• OpenShift Virtualization
• Cloud Pak for Data and all other CloudPak Applications.

While we name the two applications that have high impact on the immediate revenue, It is key to note that almost all Business critical Applications require the 'Consistency Group' requirement for Backup and DR Replication.

It can be estimated that ~40% of the revenue for OPP, ODF Advanced is impacted by lack of this feature.

Couple of Epics that are related to Consistency Groups:

• Multi Volume Consistency for DR:
• https://issues.redhat.com/browse/RHSTOR-1961 

• Multi Volume Consistency for Backup:
• https://issues.redhat.com/browse/RHSTOR-4882