AsgElectronSelectorTool: Reduce variable hardcoding + clean-up
Since there are starting to be more and more exceptions I have tried rewriting the tool to be more agnostic against possible configurations and leave as much as possible up to the config files. There is still name-of-variable -> variable value correspondence which is necessary since each variable is defined differently.
Underlying ElectronDNNCalculator now is completely agnostic against variables, expects only vector of var names in init and vector of values in evaluation with the same order. AsgElectronSelectorTool now takes variables from the config files. Using enum to fill the variable vector instead of strings which requires a bit more overhead but should have better performance?
For CF rejection, modified the code such that the mvaOutput is not recomputed but reused from the normal ID instead.
Also removed most of the tool properties as they are overwritten by the config anyway.