Adding IFFTruthClassifier output to EventSaverFlatNtuple
Adding output of new IFF TruthClassicationTool (available since AnalysisBase 21.2.143) to EventSaverFlatNtuple output. The IFF lepton-categories are stored as int-type vectors for electrons and muons (similar to the origin and type branches). The meaning of the categories can be found here.