Dont require model objects to be QObject class gen

[#71319684]
Add HeatExchangerFluidToFluid

[#71319684]
Add translate HeatExchangerFluidToFluid

[#71319684]
Add UI support for HeatExchangerFluidToFluid

[#71319684]
Remove setpoint node accessor methods

[#71319684]
Merge remote-tracking branch 'origin/develop' into 71319684-FluidHX

[#71319684]
Remove field from HX:FluidToFluid GUI inspector
Merge pull request #1061 from NREL/71319684-FluidHX

71319684 fluid hx