add back old photovaltaic.py file as photovaltaic_arcgis.py
add back old photovaltaic.py file as photovaltaic_arcgis.py

Since the daysim radiation script is not integrated, we should still
keep the old photovaltic script that runs with arcgis radiation model.

architecture-building-systems/CityEnergyAnalyst,architecture-building-systems/CityEnergyAnalyst,architecture-building-systems/CityEnergyAnalyst