hepmc3 nightly fixes 04022021 part 1
In this MR:
- New functions for
AtlasHepMC
- Small fix to
InnerDetector/InDetMonitoring/InDetPerformanceMonitoring/src/IDPerfMonZmumu.cxx
to use AtlasHepMC instead of bare HepMC - Migration to HepMC3 in
PhysicsAnalysis/TruthParticleID/McParticleTools/src/