Refactor cut-based inclusive detached dilepton trigger

Includes refactoring changes to the cut-based inclusive dilepton trigger, to be included in !4352

HLT2 rate/bandwidth comparisons, this MR (4d1acfe1) against !4352 (2612ba8c)

Rate: 5.00 kHz (5.00 kHz, +/-0.0%)

Bandwidth: 0.383 GB/s (0.383 GB/s, +0.0%)

Complete line-by-line rate comparison: hlt2_rates_comparison.md (spoiler alert, the difference is 0 for all lines)

Cc @mtat