Description
Modify G4PhysicsModelCatalog to be able to provide the unique index for
G4Track::SetAuxiliaryTrackInformation()
Voiced by G4CMP/SuperCDMS: Contact Michael Kelsey
See p. 15 of Krzysztof's talk: https://indico.cern.ch/event/1554191/contributions/6712281/attachments/3157111/5608111/IFCosmicRequirementsG420251020.pdf