Implement reference method w.r.t. single-muon triggers

The emulation method assumes that the trigger used in the denominator of the efficiency is fully efficient. This is however not obvious and should be cross-checked using a completely independent trigger, e.g. single-muon triggers. Muon objects and triggers may be added to the n-tuplew with the muon flags.

The code of getTriggerCurves should be adapted (expecting additions mostly in the event loop). The code of getTriggerTurnons might be working as such.