[controlled-lists] Add component tests

[jacobtylerwalls]

Much of the frontend logic in the controlled list manager is in components. There's very little pure typescript to test (just one function other than the API calls).

Cypress allows both e2e testing and component testing (faster, more isolated). There's also community interest in Cypress. I've had only positive experiences with it before.

Suggest writing a few component tests in Cypress for the controlled list manager. An e2e test can be added later.