stream: still inspect packets dropped by stream

The detect engine would bypass packets that are set as dropped. This
seems sane, as these packets are going to be dropped anyway.

However, it lead to the following corner case: stream events that
triggered the drop could not be matched on the rules. The packet
with the event wouldn't make it to the detect engine due to the bypass.

This patch changes the logic to not bypass DROP packets anymore.
Packets that are dropped by the stream engine will set the no payload
inspection flag, so avoid needless cost.
void DisableDetectFlowFileFlags(Flow *f)
{
    DetectPostInspectFileFlagsUpdate(f, NULL /* no sgh */, STREAM_TOSERVER);
    DetectPostInspectFileFlagsUpdate(f, NULL /* no sgh */, STREAM_TOCLIENT);
}

void DisableDetectFlowFileFlags(Flow *f)
{
    DetectPostInspectFileFlagsUpdate(f, NULL /* no sgh */, STREAM_TOSERVER);
    DetectPostInspectFileFlagsUpdate(f, NULL /* no sgh */, STREAM_TOCLIENT);
}
