add muon ID to track checker and "fix" for feature calculation with no hits
requested to merge dovombru_raaij_plyushchenko_gpu_muon_decoding into plyushchenko-gpu-muon-raw-to-hits
- Fix by @raaij for the feature calculation in the case of no hits
- Add muon ID to track checker
After adding the muons to the track checker, I noticed that the number of tracks labelled as muon by the "isMuon" algorithm varies from one execution to another. So clearly there is an issue with thread safety somewhere. At this point I'm not sure whether it comes from the muon decoding or from isMuon itself. We have to investigate this quickly!