Integrate heightmap

[holgerm]

Best would be to automatically integrate a heightmap into our new simple script approach.

[holgerm]

ToDo:

• Check how it is used in legacy code
• Load height data for given area
• Convert height data into greyscale image
• Read image and create world accordingly
• test with all surfaces and decorations etc.

[holgerm]

Possible Data Sources:

• MapBox: https://docs.mapbox.com/data/tilesets/guides/access-elevation-data/#use-the-tilequery-api
• MapTiler: https://www.maptiler.com/
• Cesium: https://cesium.com/platform/cesium-ion/pricing/
• OpenData: Bavaria: https://www.ldbv.bayern.de/produkte/opendata.html (Höhendaten Bundesweit offenbar kostenpflichtig)