MB-8789: hide data & views access for read-only admin

As per ticket, we only allow access to view definitions but neither to
view data, nor to documents.

Change-Id: Id07657e26553242017b1bf1b5a1a6269d1af7107
Reviewed-on: http://review.couchbase.org/28313
Reviewed-by: Aliaksey Artamonau <aliaksiej.artamonau@gmail.com>
Tested-by: Aliaksey Artamonau <aliaksiej.artamonau@gmail.com>