mgr/cephadm: enable ranked daemons for nfs

mgr/cephadm: enable ranked daemons for nfs

Use ranked daemons for NFS. Ganesha does not like it if multiple
instances start up with the same rank, but we need stable ranks so that
a rank can "fail over" to a new instance of a new daemon on another host
(with the same rank) for NFS client reclaim to work.

Specify a nodeid of '{service_name}.{rank}' for ganesha.

Include a unique id in the daemon_id just because this avoids some issues
with the create/destroy ordering, and because the daemon_id doesn't matter
much anymore since we are using a stable rank.

Signed-off-by: Sage Weil <sage@newdream.net>