Add test suite for login and authentication

[jescalada]

This issue will likely require completing #1275 first.

We would like to add tests for the middleware before the actual UI gets loaded. The problem, is that the tests themselves cannot be executed in dev (as they would not be able to trigger the authentication directly). We need to figure out how to execute these tests as part of the pipeline to make sure nothing breaks when pushing.

Once that is done, we want to add tests for:

• Clicking on login button takes us to the UI chooser page
• Clicking on each UI chooser button launches the respective UI
• Clicking on the Switch UI buttons (on each app) takes us back to the chooser
• Accessing UI app directly without credentials takes us back to the login page

Please add any other tests that make sense. 🙏🏻