Include PrChecker to run on the Velo tracks

• The PrChecker can be run if the cmake configuration MC_CHECK=ON
  • Depending on this compilation flag, the IDs are added to the track objects
  • Fixed the position from which the sorted LHCbIDs are read in SearchByTriplet and ConsolidateTracks
• Moved the Kalmanfilter to before the ConsolidateTracks again to access the hits in SoA from within the fit. The new track object is an AoS at the moment. Maybe we should change this in the future. The states can still be saved in an SoA in a separate container, they don't depend on the new track object. Any reasons against this?
• Renamed the source and include files in stream/handlers to all start with Handle... This is just to prevent confusion of finding the actual algorithms here rather than in the cuda/velo/... directories.
• Tried to introduce less hard-coded constants, e.g. n_modules, n_sensors, max_tracks etc. But more work is needed here.
• Added few comments. Maybe @dcampora you could add some more comments, so that new users can understand the code better. It all makes sense in the end but sometimes a little hint is helpful :-)