pybind/rbd: ensure image is open before permitting operations

pybind/rbd: ensure image is open before permitting operations

Fixes: https://tracker.ceph.com/issues/44610
Signed-off-by: Mykola Golub <mgolub@suse.com>
(cherry picked from commit 99287a1e552387f8eec505bffdffae7f4674cc8b)

Conflicts:
	src/pybind/rbd/rbd.pyx
- no "snap_exists", "snap_get_name", "snap_get_id",
  "mirror_image_create_snapshot", "mirror_image_get_mode", "config_set",
  "config_get", "config_remove", "snap_get_mirror_namespace",  in nautilus
- nautilus "mirror_image_enable" does not take any argument