Correcting and updating the energy loss formulae (was ACTS-490)

Original author Noemi Calace @ncalace

I have found few small mistakes in the implementation of the evaluation of the energy loss via ionisation. I'm correcting them, updating the code to the latest references.

Edited Mar 27, 2019 by Moritz Kiehn

To upload designs, you'll need to enable LFS and have an admin enable hashed storage. More information