Clean L1 code and fine-tune plots
Migrate HLTTauDQMOfflineSource and HLTTauDQML1Plotter to consumes API and new plotter architecture.

The consumes API does not work at all with the old architecture, where
plotter objects are constructed in beginRun(). In the new architecture
the plotters are constructed in the constructor of
HLTTauDQMOfflineSource. L1 plotter was easy as the configuration does
not change in practice after the construction. Other plotters take
some more effort, and will be migrated in subsequent commits.
Migrate HLTTauRefProducer to consumes API
Remove HLTTauDQMCaloPlotter and HLTTauDQMTrkPlotter as obsolete
Migrate HLTTauDQMPathPlotter2 to the new plotter architecture

This was also easy, as the PathPlotter2 does not use
HLTTauDQMAutomation at all.
Abstract HLT path finding etc to a new HLTTauDQMPath class
Add HLTTauDQMPathSummaryPlotter to replace HLTTauDQMLitePathPlotter
Add accepted event fraction histogram to HLTTauDQMSummaryPlotter
Obtain trigger objects from HLTTauDQMPath, infer per-filter tau/lepton multiplicities
First version of filter-offline matching, apply to EventsPerFilter
Simplify TrigTauEt/Eta/Phi filling
Fix L1-offline matching problem in EventsPerFilter histogram
Add matched version of PathTriggerBits histogram
Replace std::map with a struct for offline objects
Remove HLTTauDQMPathPlotter, HLTTauDQMLitePathPlotter, HLTTauDQMAutomation, and HLTTauDQMFilter as obsolete

The functionality of HLTTauDQMAutomation and HLTTauDQMFilter is now
essentially in HLTTauDQMPath.
Rename HLTTauDQMPathPlotter2 to HLTTauDQMPathPlotter
Clean HLTTauDQMSummaryPlotter and HLTTauPostProcessor
Update configuration
Implement offline di-object mass histogram

Needed finer-grained containers for matched offline objects (one per
object type).
Infer electron/muon multiplicities separately in HLTTauDQMPath