Now, the CephBlockPool CRD is managed with the controller-runtime.
So the watcher is outside of the main controller reconciliation loop of
CephCluster which brings numerous benefit such as:
* having its own reconciliation loop
* won't block anything from the main CephCluster controller loop
* fast than waiting for CephCluster loop to completion
Partially close: https://github.com/rook/rook/issues/1981
Signed-off-by: Sébastien Han <seb@redhat.com>
