Add support for staged systems

This adds support for:

CoilCoolingDXMultiSpeed
CoilHeatingGasMultiStage
ZoneControlThermostatStagedDualSetpoint
AirLoopHVACUnitaryHeatPumpAirToAirMultiSpeed

There is a new base class, Thermostat, which
ZoneControlThermostatStagedDualSetpoint and
ThermostatSetpointDualSetpoint derive from.

[#75620048]
Makes inletPort and OutletPort const
Merge remote-tracking branch 'origin/75620048-StagedSystems' into HVACTest

Conflicts:
	openstudiocore/src/energyplus/ForwardTranslator.cpp
	openstudiocore/src/model/CoilHeatingGas.cpp
	openstudiocore/src/model/CoilHeatingWater.cpp
	openstudiocore/src/model/ConcreteModelObjects.hpp
	openstudiocore/src/model/Model.cpp
	openstudiocore/src/model/ModelHVAC.i