Add reset function to optional fields

Add reset for AirTerminalSingleDuctVAVReheat.
Adjust terminal and coil properties.

Ensure AirTerminalSingleDuctVAVReheat::MaximumFlowperZoneFloorAreaDuringReheat is blank
Adjust defaults for hot water coils to the following regardless of
location.

Rated Inlet Water Temperature 82.2

Rated Inlet Air Temperature 16.6

Rated Outlet Water Temperature 71.1

Rated Outlet Air Temperature 32.2
Adjust VAV terminal and hot water coil properties

Set MaximumFlowperZoneFloorAreaDuringReheat to empty.
Always use default values for hot water coils.

Rated Inlet Water Temperature (82.2)
Rated Inlet Air Temperature (16.6)
Rated Outlet Water Temperature (71.1)
Rated Outlet Air Temperature  (32.2)