cephfs_mirror: Add ErrorListener to maintain blocklisted/failed timestamp in FSMirror

cephfs_mirror: Add ErrorListener to maintain blocklisted/failed timestamp in FSMirror

Have FSMirror register a listener with InstanceWatcher/MirrorWatcher which would get invoked when the mirror daemon is blocklisted or failed.
Thus FSMirror can maintain the last blocklisted/failed timestamp and use that for restarting the mirror daemon.

Fixes: https://tracker.ceph.com/issues/64927
Fixes: https://tracker.ceph.com/issues/51964
Fixes: https://tracker.ceph.com/issues/63931
Fixes: https://tracker.ceph.com/issues/63089
Signed-off-by: Jos Collin <jcollin@redhat.com>
(cherry picked from commit 77ec7bfde7a349b0e06b34ecdf328996c7642d43)