mon: deprecate CephFS inline_data support

mon: deprecate CephFS inline_data support

The plan is to start deprecating this feature now so that we can remove
it in a future release. Change it to require the
--yes-i-really-really-mean-it flag, and to emit a custom
warning when that isn't specified.

For now, we leave the testing in place since we do want to be notified
if something breaks before we're ready to rip it out completely.

Fixes: https://tracker.ceph.com/issues/41311
Signed-off-by: Jeff Layton <jlayton@redhat.com>