Optimize Performance

Sometimes queries like getting review data or get llm results take quite some time.

As far as i understood it it's enough to have the API functions async, but maybe we also have to have the functions they call async?

Do research about that, and if the way it is right now should be best practice maybe our queries can be optimized?

Maybe we should use AsyncSessions in db Dependencies and also index all features where we do filters and joins. Again, more reserach required.