feat: rewrite library state management & related refactor (#5067)

* support libraryItems promise for `updateScene()` and use `importLibrary`

* fix typing for `getLibraryItemsFromStorage()`

* remove `libraryItemsFromStorage` hack

if there was a point to it then I'm missing it, but this part will be rewritten anyway

* rewrite state handling

(temporarily removed loading states)

* add async support

* refactor and deduplicate library importing logic

* hide hints when library open

* fix snaps

* support promise in `initialData.libraryItems`

* add default to params instead

src/global.d.ts

@@ -34,6 +34,8 @@ type Mutable<T> = {
   -readonly [P in keyof T]: T[P];
 };
 
+type Merge<M, N> = Omit<M, keyof N> & N;
+
 /** utility type to assert that the second type is a subtype of the first type.
  * Returns the subtype. */
 type SubtypeOf<Supertype, Subtype extends Supertype> = Subtype;