Use react-oauth/google on frontend to simplify login logic

[Jacoberts]

I am not good at writing login flows. Most people aren't. That's why there are great libraries like react-oauth. Let's use them! My current login flow is still "valid", so adapting to react-oauth wouldn't be hard, but it will require reconsidering our endpoint authentication logic. It would be a good time to allow exposing folds to the public. Which would also be great to do before submitting the manuscript.