[Local Quivr] ABackend, I can be ran locally with a password auth

[gozineb]

Epic: #478

• • The user should be able to host the backend locally, however, we need a way to communicate securely with its backend. Therefore if the users has set its own backend URL in the settings page we should also ask him for the backend password (random string).

• Then in the backend, if the password is correct allow the query from quivr.app

Acceptance Criteria

• I can use my own backend securely with quivr.app

[github-actions]

Thanks for your contributions, we'll be closing this issue as it has gone stale. Feel free to reopen if you'd like to continue the discussion.