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. TauTruthMatchingTool will return the result of the new function in HelperFunctions.
Tested with TauAnalysisToolsExample on one file from mc16_13TeV.345123.PowhegPy8EG_NNLOPS_nnlo_30_ggH125_tautauh30h20.merge.AOD.e5814_e5984_s3126_r10201_r10210.