Overlay layers

[hauke96]

Must be done after #102.

Use the layer menu to (de)activate overlay layers with POI information, for example fire hydrants or objects with a fixme=* tag.

However, some details must be clarified.

Things to clarify

• Vector or raster data? Or both, depending on the source?
  • Example: openfiremap.de (just covers the DACH area)
• Where does the data come from?
  • Is Overpass useful for this (quota, performance, caching, ...). The OpenStreetBrowser for example also just queries overpass.
  • Is Sophox with SPARQL a better option (faster, better quota, etc.)?
  • Are there other sources?
• How bad would it be to host an own Geoserver with specific data in it? Can the data be updated regularly on one of my servers (with only a few GB of free disk space)? Or are XYZ vector tiles a better option?