Decfiles for UPC collisions

The pipelines are failing. However, for the run-gauss job, it seems to be a timeout error. It runs locally for me with Gauss49r24 but does take about 30mins. I believe this is due to a long initialisation stage for Starlight.

For the check-decfile job I followed the naming convention as best I can but it doesn't pass the general flag check. I am happy to rewrite the event types in case I have misunderstood the convention.

It will be great if this file could be made available for Sim10.