component file sharing: quotas implementation: quotas can now be specified using the `quotas_json` option of `component file_sharing` section in settings. This must be a dict where: - `users` key contains default quotas for all users - `admins` key contains quotas for administrators (not implemented yet) - `jids` contain bare JID to quota mapping, to have user-specific quota The value can be either a int for quota in bytes, or a case insensitive string with an optional multiplier symbol (e.g. "500 Mio"). `None` can be used for explicit unlimited quota (which is the default is `users` is not set). When a file size is too big for quota, upload is refused with an error message indicating allowed quota, used space, and the size of the file that user wants to upload.

Those certificates are used to activate TLS for end-2-end testing (to be as
close as possible as production environment), they are used in other containers
needing TLS certificates (notably Prosody).

To generate them, minica has been used. Minica can be found at https://github.com/jsha/minica.

The following commands have been used:

$ minica --domains "server1.test,*.server1.test,server2.test,server3.test,libervia-backend.test,libervia-web.test"
$ chmod 0644 minica.pem server1.test/cert.pem && chmod 0640 server1.test/key.pem

Note that certificates are valid for 2 years and 30 days, so they must be renewed after this delay.