Merge LowEGJet and HighEGJet samples

The HLT_PFJet triggers are spread among two data sets: LowEGJet and HighEGJet. The former contains triggers with thresholds at 15, 25, 40, 60; the latter does contain certain events with the same triggers, but also additional ones with thresholds at 80, 140, etc.

Alternatively, we may want to combine ZeroBias and HighEGJet. In high-PU analyses, we could as well want to use the ZeroBias trigger to cover the phase space below the first turn-on point. For ZeroBias, we do have applyZeroBiasNormalisation that includes a maxpt option, but we would need a more general skimmer.

A priori, writing a skimmer to achieve this should not be difficult, but we should avoid having too many skimmers and try to come up with a general strategy that could cover similar cases. I leave this issue open to collect ideas and remarks.