Advanced solar panel visuals

New 3D panels for solar energy, including 3D models on flat roofs, parking lots and noise barriers with solar panels and solar panels floating on water. Also the SOLAR_PANEL attribute was added, for easier upgrade of multiple buildings or for combining several attributes on the same building (such as isolation ).

Documentation:

https://support.tygron.com/wiki/Solar_panels_(Function_Value)

https://support.tygron.com/wiki/Align_elevation_(Function_Value)