nas5gs: Add dissection of QoS flow descriptions.

While there renumber according to latest spec. and fix some indentation.

Change-Id: Ib9b4590d72c3124ffcb96fd719a9a19cadb4c494
Reviewed-on: https://code.wireshark.org/review/31300
Petri-Dish: Anders Broman <[email protected]>
Tested-by: Petri Dish Buildbot
Reviewed-by: Anders Broman <[email protected]>

Author: AndersBroman