Make public database

[guillefix]

The public data is currently stored in files in my server. See here for current implementation, where files are stored in folders organized by world and session, in a data folder. Currently there's no search functionality or names given to the recordings.

We need to make a database that keeps them more organize, and assigns them metadata like name, recording time, world where it was recorded, etc.

This would then allow to add an interface for searching the data both on Neos and on the web.

We will probably move the database to a better cloud infrastructure (see MetaGenAI/info#4)