Update GEM local DAQ format to v302a
This MR contains mostly cherry-picked commits from !102 (closed) with the goal to integrate the new GEM local DAQ format before the new GEM data format. The readout local DAQ application is almost ready while the unpackers are still being worked on. Prompt testing and deployment would be more than useful. This is also why the payload minimum and maximum size can now be configured through registers for GEM.