Updates for SVJ analysis
- add Hidden Valley, dark matter PDG IDs to keep in gen particles
- add more Zprime cross sections
- store "isHV" truth-level tag for AK8 jets to denote production from Hidden Valley quark
- store GenJet multiplicity
GitLab jobs artifacts no longer stored forever as of Monday, November 4th 08:30h. Further information under https://cern.ch/otg0152576