[VMOwnedVolumes][Draft] State based gaurading and failure recovery handling

[deepakkinni]

What this PR does / why we need it:
Phase 3 — Workflow C: Detach, CSI Side (Section 9.3)
vCenter Snapshot Tree Query (C.6) — Implement a helper that fetches mo:VirtualMachine { snapshot }, batch-fetches config.hardware.device for all snapshot MoRefs, and builds a set of diskUUIDs still referenced by at least one remaining vCenter snapshot.

Detach Reconciliation: Mark Snapshot-Retained (C.6.a) — When snapshot tree query shows the disk is still referenced, transition CVI to VM_MANAGED + vmName="" (snapshot-retained), patch PVC label to retained-by-snapshot, and remove the volume from BA status.

Detach Reconciliation: Re-Register as FCD (C.7) — When no vCenter snapshot references the disk, reconstruct CNS metadata from PVC/PV/CVI, call CnsCreateVolume to re-register the FCD, transition CVI to CSI_MANAGED, remove cvi-protection finalizer, label PVC csi-owned, and clean up BA status.

Metadata Reconstruction for Re-Registration (Section 9.4) — Implement the metadata reconstruction utility that reads PVC labels/annotations, PV name, and CSI config (ClusterID, SupervisorID) to build the CnsCreateVolume metadata payload used by both C.7 and D.6.

Revert-Induced Drop Handling (C.5/C.6) — Detect volumes with BA condition VolumeDetached=True, reason=DroppedBySnapshotRevert, ensure CVI is set to TRANSFERRING_TO_CSI if not already, and proceed through the same C.6 snapshot-tree-query and branching logic.

Phase 4 — Workflow D: Snapshot Deletion, CSI Phase (Section 10)
VMSnap Watch + CSI Finalizer Trigger (D.3) — Add a watch on VirtualMachineSnapshot CRs; when CSI observes conditions[SnapshotDeleted]=True with its csi.vsphere.vmware.com/snapshot finalizer still present, begin Phase 2 disk re-evaluation.

Per-Disk Retention Evaluation (D.4/D.5) — For each disk in VMSnap.status.disks, look up CVI by cns.vmware.com/disk-uuid label, check the remaining vCenter snapshot tree (reuse helper from task 13), and branch: still-retained (no-op), re-adopted by VM (no-op), or no snapshots remain + vmName="" (proceed to D.6).

Re-Register on Last Snapshot Deletion (D.6) — Same re-registration logic as C.7 (reuse task 15/16) but triggered from Workflow D; transition CVI from VM_MANAGED (snapshot-retained) to CSI_MANAGED, remove cvi-protection finalizer, label PVC csi-owned.

CSI Finalizer Removal from VMSnap (D.7) — After all disks in status.disks are processed, remove the CSI finalizer from the VMSnap CR to allow K8s garbage collection.

Deferred PVC Deletion After D.6 (Section 13.2.2) — After D.6 completes and the PVC has a deletionTimestamp (webhook was bypassed during retention), release the CSI volume-protection finalizer so the standard FCD delete path can proceed.

Which issue this PR fixes (optional, in fixes #<issue number>(, fixes #<issue_number>, ...) format, will close that issue when PR gets merged): fixes #

Testing done:
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PR needs rebase.

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