openSAFETY: Separate definitions into header

openSAFETY: Separate definitions into header

 To allow future tap interfaces as well as analysis plugins
 to use the same definitions the dissector used, all defines
 are being separated into a header file

Change-Id: Iec38e361ded46aab6684c2713ba9a047193a6694
Reviewed-on: https://code.wireshark.org/review/7468
Reviewed-by: Roland Knall <rknall@gmail.com>
Petri-Dish: Alexis La Goutte <alexis.lagoutte@gmail.com>
Tested-by: Petri Dish Buildbot <buildbot-no-reply@wireshark.org>
Reviewed-by: Anders Broman <a.broman58@gmail.com>