CBQE-1621 add api for zone info
and get group name

Change-Id: I8ac9f9c0bbafe8aefa92a43307db0be9cac29216
Reviewed-on: http://review.couchbase.org/30039
Tested-by: Thuan Nguyen <soccon@gmail.com>
Reviewed-by: Tommie McAfee <tommie@couchbase.com>