Modifications to the histogram plotters for release 22

The release 22 timing histograms all have a different format and naming convention in the expert histograms

These changes to the cpucost plotting code allow the timing plots to be created more easily

NB: the code in this package is not used as part of athena, but builds standalone executables only used for the ID Trigger nightly tests. No required CI test executions run this code, or are affected by it.