Expand dissection of 8.108 Presence Reporting Area Action.

Change-Id: I2ad57d8cdb6758f01146b37ac924e2d8f2141546
Reviewed-on: https://code.wireshark.org/review/4491
Petri-Dish: Anders Broman <a.broman58@gmail.com>
Tested-by: Petri Dish Buildbot <buildbot-no-reply@wireshark.org>
Reviewed-by: Anders Broman <a.broman58@gmail.com>