MB-8903: Add erange response to fake server

The fake server now handles Stream Requests the same way as
ep-engine when the start sequence number is higher than the
end sequence or the current high sequence of the partition.

Change-Id: I80c27b47922d8cb28eca5ee76e384f389b75899f
Reviewed-on: http://review.couchbase.org/32326
Tested-by: buildbot <build@couchbase.com>
Reviewed-by: Volker Mische <volker.mische@gmail.com>