In view of the upcoming heavy-ions run, this MR tries to update the web display of the HLT muon histograms, which currently looks for an outdated set of monitoring plots that often do not exist anymore. The new hanconfig does this a way which tries to be as regexp-generic as possible, and mimicks what is done for pp collisions (and extends it in a more general way).
This MR was somehow triggered by the resolution of ATR-27787 by !65467 (merged) - which addressed the fact that the muon trigger monitoring code actually crashed when trying to generate these histograms. ATR-28130 tracks the overall status of hanconfig changes needed for the heavy-ions run.
How was this tested? Besides the hanconfig syntax tests, I produced a couple of webdisplays. It was impossible to produce them with the actual set of histograms from a recent HI reprocessing, since we don't have such reprocessings (muon monitoring was disabled in those advertised by ATR-28130), so I had to make some compromise. The webdisplays which indicate this MR should work are therefore:
https://atlasdqm.cern.ch/webdisplay/test/12300/express_express/run_451094/run: a test running over a high-statistics pp DQ HIST output file, produced in a previous reprocessing with the pp menu, showing that the hanconfig is generic enough to work smoothly regardless of the set of monitored HLT chains in the menu
