Implementation of jXE Multiplicity

Changes implemented:

• XEMultiplicity class name and file changed to EnergyThreshold, to bring in line with menu.
• Enable EnergyThreshold items in TopoSteering, and filtering for gFEX items that are not yet implemented.
• Changing Types.cxx to return the correct mapping for jXE input and the MET class
• Changing EnergyInputProviderFEX to fill EtDouble.
• Enable EnergyInputFEX in TopoSimulationConfig.
• Update the Trigger Test counts to reflect enabled jXE thresholds

Tagging @orlando @iriu @paulama @asonay

ATR-24653