ISF_Event: const fixes for Truth
Provide const-correct accessors for:
ITruthIncident::parentParticle()
TruthBinding::getTruthParticle()
Tested also in HepMC3 build.
Provide const-correct accessors for:
ITruthIncident::parentParticle()
TruthBinding::getTruthParticle()
Tested also in HepMC3 build.