Add a new representation called geojson, which exposes the full response as GEOJSON, not only the geometries

[Piiit]

The intermediate step could be to do the following: The old coordinates are not represented as geojson, however we could maybe add a flag to the api to transform them into a geojson as well.

The final step however would be a full geojson output, which could then be fed into leaflet or any other geojson aware tool