optimize traffic for editor geometries / cache objects locally

src/c3nav/mapdata/models/geometry/base.py

@@ -52,6 +52,9 @@ class GeometryMixin(SerializableMixin):
             result['bounds'] = True
         return result
 
+    def get_geojson_key(self):
+        return (self.__class__.__name__.lower(), self.id)
+
     def to_geojson(self, instance=None) -> dict:
         result = {
             'type': 'Feature',