Hiking dataset uses non-standardized Gps track fields

[Luscha]

Some datasets use references to GeoShape api to link to geojson shapes using a structure similar to:

"GpsTrack": [
    {
      "Id": "routes-hikingtrails.10213410",
      "Type": "Track",
      "Format": "geojson",
      "GpxTrackUrl": "https://api.tourism.testingmachine.eu/v1/GeoShape/routes-hikingtrails.10213410",
      "GpxTrackDesc": null
    }
  ],

the nature of the structure makes difficult to configure a "resolver" to get the actual shape to show the track on maps like the databrowser map view.
The primary problem is that even if we can make "GpsTrack" field configurable in the metadata API, adding a second layer of configuration to find the geoshpae url ("GpxTrackUrl") would make the metadata api full of specific logics we need only for the databrowser.

The best solution would be to use the standardized "Geo" field containing well-known GeoData structures.