mds: create file system with specific ID

mds: create file system with specific ID

File system will need to be recreated when monitor databases are lost
and rebuilt. Some applications (e.g., CSI) expect that the recovered
file system have the same ID as before. Allow creating a file system
with a specific ID to help in such scenarios. This can now be done by
the `fs new` command using the argument 'fscid' and 'force' flag.
Newer file systems will no longer have increasing IDs as a corollary.

Fixes: https://tracker.ceph.com/issues/51340
Signed-off-by: Ramana Raja <rraja@redhat.com>
(cherry picked from commit a0a8ba5087f0b82588860cda188dfdb48a964771)

Conflicts:
	qa/tasks/cephfs/test_admin.py
        fixed conflicts due tests reorder in master