Add FILE_UPLOAD_ENABLED setting (default to False, to avoid
a breaking change). Also adds a max_count_by_user sub setting
to restrict the number of uploaded files per user.
Remove the user-provided filename while preserving the extension,
and switch to the format `uuid.extension`.
This is more natural than the previous `uuid/.extension` format
and avoids confusion.
Update related tests accordingly.
For the coming features we will need to store files on the meet side.
(for instance user backgrounds).
This commits adds a new Model to manage files, and the associated
serializers & viewsets. All are tested.
This work was heavily inspired by the work done by our friends at
https://github.com/suitenumerique/drive
It build on the same architecture design (upload directly to S3 but
download goes through our proxy), but model is much much simplier
(no folders, no file sharing, etc.).