MB-9869: Ensure datatype set is not spurious

- If datatype exceeds allowed values:
PROTOCOL_BINARY_RAW_BYTES=0x00
PROTOCOL_BINARY_DATATYPE_JSON=0x01
PROTOCOL_BINARY_DATATYPE_COMPRESSED=0x02
PROTOCOL_BINARY_DATATYPE_COMPRESSED_JSON=0x03

, return ENGINE_EINVAL, to notify client about
invalid argument.

Change-Id: I1af09034e520a1e6c7fae7afa99bee124ea21540
Reviewed-on: http://review.couchbase.org/33648
Reviewed-by: abhinav dangeti <abhinav@couchbase.com>
Tested-by: abhinav dangeti <abhinav@couchbase.com>