Add MET+HT versions of some DarkJet/SVJ chains to Dev Menu
This MR adds pfopufit and nn MET legs to some delayed and support DarkJet/SVJ chains. MET is part of the discriminating variable for the SVJ+l analysis, and work is in progress to add an online MET to the PEB chains. These changes will trial the online met in the full-build versions, assess CPU impact and provide a proof-of-principle for using online MET in the analysis. Adding MET to the PEB chains requires further work, and this will follow in a future MR. See ATR-21596 for more info.