queryport: Use bytes type for equal parameter in scan requests

Changed equal parameter to bytes. Also added missing equal
parameter to the scan and stats requests.

Change-Id: I9d330d7450ae498033d38e1d133b21defd592170
Reviewed-on: http://review.couchbase.org/43032
Reviewed-by: Pratap Chakravarthy <prataprc@couchbase.com>
Reviewed-by: Sarath Lakshman <sarath@couchbase.com>
Tested-by: Sarath Lakshman <sarath@couchbase.com>