PB-8121 kubevirt support for vmInstancetype and vmPreference

[vsundarraj-px]

What type of PR is this?

Uncomment only one and also add the corresponding label in the PR:
bug
feature
improvement
cleanup
api-change
design
documentation
failing-test
unit-test
integration-test

What this PR does / why we need it:
This PR enhances kubevirt support for Px-backup by enabling support for virtualMachinePreference and VirtualMachineInstancetype.

Does this PR change a user-facing CRD or CLI?:

no
Is a release note needed?:

Issue: VirtualMachineInstancetype and VirtualMachinePreference are not backed up with VM backup or NS backup types
User Impact: Customer backups of VMs either through NS backup or through VM backup will fail to restore
Resolution Upgrade to the fixed version of stork to get the support.

Does this change need to be cherry-picked to a release branch?:

VMs with instancetype and preference are backed up and restored to new cluster and new NS
Regression test for VMs with secrets, configmaps and PVCs