Resolve first part of ATLTAU-1639 "21.2 "
Resolves first part of ATLTAU-1639
Replace duplicate checkTruthMatch() function with general getTruthMatchType() in HelperFunctions because it does not rely on any class object information.
Tested with TauAnalysisToolsExample on one file from mc16_13TeV.345123.PowhegPy8EG_NNLOPS_nnlo_30_ggH125_tautauh30h20.merge.AOD.e5814_e5984_s3126_r10201_r10210.