cephadm: handle adopting offline OSDSs

cephadm: handle adopting offline OSDSs

The current adopt behavior expects OSDs to be online, in order to read
/var/lib/ceph/osd/ceph-$ID/fsid.  To handle the case where OSDs
are offline, this change first checks to see if that file is present,
and if not, falls back to calling `ceph-volume lvm list` to see if
there's a matching OSD there, and if that doesn't work, it checks
/etc/ceph/osd/*.json to see if there's a matching old-style simple
OSD present.

For LVM OSDs, the only thing we need is the ODS's fsid; the remainer
of the adopt procedure "just works", as the various other files
in /var/lib/ceph/$FSID/osd.$ID are created by magic anyway when the
OSD is activated, so it doesn't matter if they're not present at
adoption time.

For simple (ceph-disk created) OSDs, we actually need all the files under
/var/lib/ceph/osd/ceph-$ID/ to be moved to /var/lib/ceph/$FSID/osd.$ID
so if a simple OSD is found, it's mounted first, so the existing
move_files() a bit further down around line 3200 continues to work.

Fixes: https://tracker.ceph.com/issues/45095
Signed-off-by: Tim Serong <tserong@suse.com>