adding HGTD variables in JETM2
Adding TrackingVariablesHGTD = ["HGTD_cluster_time", "HGTD_extrap_x", "HGTD_extrap_y"] for HL-LHC derivations. JETM2 derivation is used for quark gluon tagger development. Slides showing size comparison can be found here: https://indico.cern.ch/event/1463185/