TriggerRatesMonitor: monitor L1 and HLT rates
TriggerRatesMonitor: monitor dataset rates
TriggerRatesMonitor: fix the booking of L1 rate histograms
TriggerRatesMonitor: downgrade assert to LogWarning
TriggerRatesMonitor: make L1 histogram names more uniform
TriggerRatesMonitor: add monitoring plots for HLT streams
TriggerRatesMonitor: make HLT histogram names more uniform
Merge pull request #5966 from fwyzard/TriggerRatesMonitor_72x

port L1 and HLT rate monitoring via DQM to 7.2.x