MB-12965: MB-12941: improved service labels formatting

Change-Id: I34db299f9d9601ad38f73a51df86ac84e8fb3f55
Reviewed-on: http://review.couchbase.org/44488
Reviewed-by: Aliaksey Kandratsenka <alkondratenko@gmail.com>
Tested-by: Aliaksey Kandratsenka <alkondratenko@gmail.com>