Support Cryptomator Hub vaults

### Summary

As an admin, I would like to be able to unlock a Cryptomator Hub vault, e.g. to create backups.

### Motivation

In certain circumstances, in very secure environments, it may be useful to create backups of the contents of the vaults. For this purpose it is necessary that Cryptomator CLI can unlock Hub vaults.

### Anything else?

If you need this feature in a timely manner, you may want to consider sponsoring this feature. Contact us at support@cryptomator.org for further information.

With sponsored features, the requirements are driven by the sponsor, but the resulting feature is available to everyone using Cryptomator. Instead of custom work, sponsors are willing to contribute features back to our platform so that all Cryptomator users can benefit! Also, sponsoring a feature is cheaper than custom development.