Inaccessible data in Geant4

There is some data in Geant4 which we currently can’t access but which we may need to import to make sure we’re doing the everything the same in Celeritas:

• Energy loss step function parameters (dRoverRange and finalRange). These are set with G4EmParameters::SetStepFunction()
• MSC parameters such as range factor, safety factor, lambda limit, step limit type. The default values are accessible through G4EmParameters, but these can be overridden through the model setter methods (e.g. G4VMscModel::SetRangeFactor()). This is done, for example, in the CMS physics list for the MSC model used in the HCAL and HGCAL regions.