Remove previously loaded scenes (#734)

As mentioned in #724, the current implementation is suboptimal. Let's remove it until we come back with a better design.

Fixes #724

src/scene/index.ts

@@ -16,8 +16,6 @@ export {
   saveToLocalStorage,
   exportToBackend,
   importFromBackend,
-  addToLoadedScenes,
-  loadedScenes,
   loadScene,
   calculateScrollCenter,
 } from "./data";