add packages needed for Pythia8.3, introduce corrections for jet filters, add MultiBjetFilter
In order to fix the ART tests, some changes already available in 21.6, need to be added to master. In this MR some packages needed for Pythia8.3xx are installed in External/Pythia8/CMakeLists.txt and MultiBjetFilter is added to GeneratorFilters.
Additionally, GenerateTruthJets.py file is corrected to take into account the changes introduced in JetRec package in master (and not present in 21.6)