cephfs,mon: require confirmation to fail unhealthy FS

cephfs,mon: require confirmation to fail unhealthy FS

Confirmation flag must be passed when running the command "ceph fs fail"
when the MDS for this FS has either of the two health warnings: MDS_TRIM
or MDS_CACHE_OVERSIZED. Else, the command will fail and print an
appropriate error message.

Restarting an MDS with these health warnings is not recommened since it
will have a slow recovery during restart which will create new problems.

Fixes: https://tracker.ceph.com/issues/61866
Signed-off-by: Rishabh Dave <ridave@redhat.com>
(cherry picked from commit b901616494a8359e59f7ec2cd661077c4aced01c)

Conflicts:
- src/mon/FSCommands.cc
  -  lines surrounding the patch are different in reef compared to main.
     the reef code was still accessing "mds_map" directly instead of
     accessing it using "get_mds_map()".
  - return value of get_filesystem() is different in main.