Return TruthTaus from truth matching tool in SUSY tools
Currently tau truth matching tool is only called on reco tau jets which then retrieve/creates the TauJets container.
Adding a call to retrieve truth taus in GetTaus, which will be called prior to null pointer checks.
Adding a function which allows user to retrieve/create the TauJets container without having to go through matching on reco TauJets.
Closes OPEN3GEN-23