Upgrade MiniTel example to serve as example for issue https://github.com/AIDASoft/DD4hep/issues/1091

Allow users to add track user information to G4 tracks, which then moves to Geant4Particle for saving

Always use Geant4 units, as written out by ddsim root I/O

If we do not already store particles that become important'ish later we get a fatal error because the equilavent finding might not be able to find this particle

Add track momentum to the MonteCarloContribution of Geant4Hit structures. See issue https://github.com/AIDASoft/DD4hep/issues/1037