MM L1 Simulation - Private members instead of functions
Cloning from !59909 (closed) due to the issue there with the gitlab pipeline:
In order to reduce memory load in some recurrent algorithms, private members are used directly in the corresponding classes, instead of calling several time the same functions. Arguments are passed by reference in such cases
Also addressing the comment from !59930 (merged) about the missing variable in MMT_Hit.cxx