Use snapshot during clone

[dsessler7]

Checklist:

• [x] Have you added an explanation of what your changes do and why you'd like them to be included?
• [ ] Have you updated or added documentation for the change, as applicable?
• [ ] Have you tested your changes on all related environments with successful results, as applicable?
  • [x] Have you added automated tests?

Type of Changes:

• [x] New feature
• [ ] Bug fix
• [ ] Documentation
• [x] Testing enhancement
• [ ] Other

What is the current behavior (link to any open issues here)?

Currently, the VolumeSnapshots that are created are not used by the operator. A user would have to manually target them.

What is the new behavior (if this is a feature change)?

• [ ] Breaking change (fix or feature that would cause existing functionality to change)

Now, when a postgrescluster clone is being created from another postgrescluster and the source cluster has VolumeSnapshots turned on and has a ReadyToUse snapshot available, the VolumeSnapshot will be used to create the pgdata pvc.

Other Information: