Move and merge common particles
Code from Hlt2Conf and RecoConf is copied into Phys/DaVinci here https://gitlab.cern.ch/lhcb/DaVinci/-/blob/master/Phys/DaVinci/python/DaVinci/common_particles.py . That was needed to get DPA going, but is dangerous as it might diverge.
Can some of that be moved to Rec? @dfazzini will investigate.