Changes to read and using the express stream prescale ATR-21324,ATR-20870
- duplicate name parameter removed from HLTPrescale json ATR-20877
- add express stream maps to HLTPrescaleSet DataStructure and functions to access
- includes returning default if chain not in express
- Update PrescalingTool to read express prescale see getPrescale
- Update StreamTagMakerTool to check express stream prescale for relevant chains
cc @rbielski