Closes#145.
All the backend should be implemented here, ~~I just don't know how to make a download button on the frontend.~~ I made a button, we'll see if it works.
- [x] ~~Add asset download api key to infra~~ this was never required
Reviewed-on: #201
Co-authored-by: Quaternions <krakow20@gmail.com>
Co-committed-by: Quaternions <krakow20@gmail.com>