Authenticate using Google SSO

[Marcelixoo]

As a student I would like to login using my @code.berlin account and stay logged in as long as my session is still valid on my device.

Koha already handles login with Google accounts and will, therefore, be responsible for the whole orchestration of the authentication workflow. This task scopes the work necessary to integrate with Koha’s backend and properly exchange tokens that can be used by the frontend application to make further requests to its API.

Acceptance Criteria

• Students can login to the application using their @code.berlin accounts.
• Further requests made to the API are bound to the permissions imposed to the currently logged in account.