Missing geom for HD Views in /trek/ APIv2 route

[Chatewgne]

geometry from HDViewPointSerializer is failing silently when accessed through /trek/ route

       "view_points": [
           {
               "create_datetime": "2023-08-29T09:23:17.896176Z",
               "update_datetime": "2023-09-07T12:27:51.272475Z",
               "id": 20,
               "annotations":  null,
               "author": "",
               "legend": "",
               "license": null,
               "metadata_url": "http://geotrek.local:8000/api/hdviewpoint/drf/hdviewpoints/20/info/metadata",
               "picture_tiles_url": "http://geotrek.local:8000/api/hdviewpoint/drf/hdviewpoints/20/tiles/%7Bz%7D/%7Bx%7D/%7By%7D.png?source=vips",
               "poi": null,
               "title": "bigff",
               "site": null,
               "trek": {
                   "uuid": "820d9e27-3edc-40c5-93b9-7662387a9150",
                   "id": 396
               },
               "thumbnail_url": "http://geotrek.local:8000/api/hdviewpoint/drf/hdviewpoints/20/data/thumbnail.png?source=vips",
               "uuid": "43f1c4fa-4bfa-415d-9761-2ae876868f0c"
           }
          ]

We need to make sure it is properly serialized as follow

       "view_points": [
           {
               "create_datetime": "2023-08-29T09:23:17.896176Z",
               "update_datetime": "2023-09-07T12:27:51.272475Z",
               "id": 20,
               "annotations":  null,
               "author": "",
               "geometry": {
                   "type": "Point",
                   "coordinates": [
                       3.4409666,
                       44.1214521
                   ]
               },
               "legend": "",
               "license": null,
               "metadata_url": "http://geotrek.local:8000/api/hdviewpoint/drf/hdviewpoints/20/info/metadata",
               "picture_tiles_url": "http://geotrek.local:8000/api/hdviewpoint/drf/hdviewpoints/20/tiles/%7Bz%7D/%7Bx%7D/%7By%7D.png?source=vips",
               "poi": null,
               "title": "bigff",
               "site": null,
               "trek": {
                   "uuid": "820d9e27-3edc-40c5-93b9-7662387a9150",
                   "id": 396
               },
               "thumbnail_url": "http://geotrek.local:8000/api/hdviewpoint/drf/hdviewpoints/20/data/thumbnail.png?source=vips",
               "uuid": "43f1c4fa-4bfa-415d-9761-2ae876868f0c"
           }
          ]