client: expose ceph.quota.max_bytes xattr within snapshots

client: expose ceph.quota.max_bytes xattr within snapshots

For directories within snapshots, expose the ceph.quota.max_bytes
extended attribute information. This enables fetching quota
information when the snapshot was taken and is particularly useful
when cloning subvolume snapshots, to enforce the quota on the
clone subvolume as well.

Fixes: https://tracker.ceph.com/issues/46278
Signed-off-by: Shyamsundar Ranganathan <srangana@redhat.com>
(cherry picked from commit 35a033f576a7bcbe89bc96c05eefc6d47ede8fc5)