in the existing node watcher, we'll check for node update
event and see if there are `out-of-service` taints are applied
and `ROOK_WATCH_FOR_NODE_FAILURE` is enabled in rook-ceph-operator-configmap,
if then we'll create the networkFence cr and delete the cr if nodes come back.
And, added the unit test too.
Signed-off-by: subhamkrai <srai@redhat.com>