Use trigger object matching when calculating tau trigger SF

[ktht]

This should be particularly relevant in 0l+4tau and 1l+3tau, where we don't necessarily know which of the selected taus triggered the di-tau or lepton+tau cross-trigger, which is the reason why the current code tries all possible permutations of various triggering scenarios to estimate the SF. Unless I'm missing something crucial here, the ambiguities can be resolved by finding the trigger(s) that the selected hadronic taus have fired, and compute the SF just for those trigger(s).