show response body for clone

[boddumanohar]

Currently the V2 volume clone endpoint:

GET /api/v2/clusters/{cluster_id}/storage-pools/{pool_id}/volumes/{lvol_id}/clone

can return HTTP 500 because it directly returns:

return lvol_controller.clone_lvol(...)

clone_lvol() returns a tuple, for example (new_lvol_uuid, False) on success or (False, error) on failure, while the route is annotated as:

def clone(...) -> bool:

FastAPI tries to serialize/validate that tuple as a boolean and raises ResponseValidationError.

The these changes fixes this by unpacking the tuple, handling the error case explicitly, and returning the created clone using the same V2 creation pattern:

HTTP 201 Created
Location: /api/v2/clusters/<cluster_id>/storage-pools/<pool_id>/volumes/<new_clone_volume_id>/
Body: empty