Import a few more EM parameters from Geant4#703

Merged

sethrj merged 2 commits intoceleritas-project:developfrom amandalund:import-params

Mar 28, 2023

+128-31

Commits on Mar 27, 2023

Import lowest electron energy from Geant4 and rename eloss_calc_limit
amandalund
committed

Commits on Mar 28, 2023

Import MSC parameters from Geant4
amandalund
committed