server sided external api calls (#697)

* server sided external api calls

* fix uploading gpx files

* rename api/v1/nominatim with api/v1/geocoding to prepare photon support

* remove NOMINATIM_MAX_RETRIES (side-kick from other PR)

* re-add nominatim url fallback

* docu, env var defaults and fallbacks, docker compose files

* refactor

* furhter refactorings and fixes

* PUBLIC_VALHALLA_ENABLED in docker compose files added

* fix env var names

---------

Co-authored-by: Flomp <Flomp@users.noreply.github.com>

docker/docker-compose.dev.yml

@@ -52,9 +52,9 @@ services:
       UPLOAD_FOLDER: /app/uploads
       UPLOAD_USER:
       UPLOAD_PASSWORD:
-      PUBLIC_OVERPASS_API_URL: https://overpass-api.de
-      PUBLIC_VALHALLA_URL: https://valhalla1.openstreetmap.de
-      PUBLIC_NOMINATIM_URL: https://nominatim.openstreetmap.org
+      OVERPASS_API_URL: https://overpass-api.de
+      VALHALLA_URL: https://valhalla1.openstreetmap.de
+      NOMINATIM_URL: https://nominatim.openstreetmap.org
     volumes:
       - uploads:/app/uploads
       # - ./data/about.md:/app/build/client/md/about.md