Update FanOnOff, exclude ZoneHVAC:UnitHeater

For some reason I thought ZoneHVAC:UnitHeater used Fan:OnOff but it
does not.
Update ForwardTranslators to out put air inlet/outlet nodes

Found during E+ integration tests. The fan’s air{inlet,outlet}node
needs to be set in the containing hvac component. This is added to the
respective ForwardTranslators.