Remove inactive/obsolete files

I have identified a number of classes in the include/sim3a folder that do not appear to be actively used anywhere in the sim3a project. I am wondering if these were only included for historical reasons, e.g., Jonas may have used them for analyzing data from the I161 experiment? In any case, I have moved all these "inactive" files to the to_be_removed folder for now with the intention of deleting them later once we know for sure that they aren't needed.