[web interface] Add Django interfaces to avoid using CLI

[sveetch]

Is your feature request related to a problem? Please describe.

Currently Diskette is command line only application.

Describe the solution you'd like

• [ ] Admin interface Diskette has no models so it would be custom an admin view. It could help to manually create an archive without to use command line. Also it could be able to generate new API KEY and revoke previous one. Also it could hints about storage sizes that would be dumped.
• [ ] Endpoint First need is an endpoint that can be called from diskette_load to get a dump archive that can be directly downloaded then loaded locally. Dump creation are still required to be created from the admin. This need to be securized with an API KEY.

[sveetch]

Admin interface is the first priority since API itself is useless without admin.

Fact is, the API should not be able to trigger creation of a dump, only to get it. This is because API with full power rights could cause issues since dump creation can be resource consuming and admin is a little more safer to avoid user mistakes.

Finally, the admin interface is more useful since it can quickly perform dump creation so it should level up Diskette usefulness sooner than implementing API first.