WIP: CP algs: Add ElectronAnalysisHelpers for SF functions
This is a first step to add some helper functions for common algorithms that people might need. I started with electrons but I plan to extend this also to some other objects.
@krumnack, I know you did not like this idea that much originally but it would be really nice if I can get some feedback. Mainly I added new ElectronAnalysisHelpers.py file which contains addXXXXX functions to add mainly scale factor algorithms. Some of those methods are actually then re-used in the main sequence to avoid duplication. Especially trigger SFs users will add on their own so I do not plan to add them to the main sequence for the time being.