Updates to TRUTH5 and truth infrastructure
Protecting additions of jet finders and getters in MCTruthCommon. This allows multiple truth formats to be run at the same time (yay!).
Splitting off collection helpers from the hard scatter collection. In principle these are more general, and I don't want to copy-paste code when making new collections later.
Several updates to TRUTH5: adding fat jets, adding W-boson decays (both of these were a part of TRUTH3 already), and using common helper functions for the addition of collections to the output file.
For info @jcatmore