Lepton SF + control regions

Lepton SF from correctionlib. Attached only in leptonic categories, based on the leading lepton contained inside the higgs jet.

Top pt reweighting on ttbar.

Control regions, currently from any categories with either hbb or htt failing i.e. 0.5 < 9hxx < loose cut. Control regions set to be always unblinded by default.

CL arg in combine step to attach a rateparams to processes. Defaults to none. One common rateparam for a given process, throughout all categories. Process tag is as sample.py i.e. QCD, VX, TX, ...