radosgw-admin: period pull command is not always a raw_storage_op

radosgw-admin: period pull command is not always a raw_storage_op

if a --url is given, 'period pull' does not depend on any zone/period
configuration and can be a raw_storage_op. if we get a --remote instead,
we do need to initialize the zone/period configuration to find the
correct endpoint/access keys

Fixes: https://tracker.ceph.com/issues/47217
Signed-off-by: Casey Bodley <cbodley@redhat.com>
(cherry picked from commit 2b44a9d060d33dca9768c758e1908365488aac2a)

Conflicts:
	src/rgw/rgw_admin.cc
- nautilus has different (but unrelatedly so) raw_storage_ops_list