flow/stream: reduce/disable pseudo packet injections

flow/stream: reduce/disable pseudo packet injections

At flow timeout, we no longer need to first run reassembly in
one dir, then inspection in the other. We can do both in single
packet now.

Disable pseudo packets when receiving stream end packets. Instead
call the app-layer parser in the packet direction for stream end
packets and flow end packets.

These changes in handling of those stream end packets make the
pseudo packets unnecessary.