Move the `noToken` option for retrieving books to implicit

Currently, we have an endpoint for getting books without a token (`getBooksNoToken/`) as well as an endpoint for getting them when you are logged in (with a token, `getAllBooks/`). Instead, we should move to one endpoint that uses `auth.optional`, and if a token is provided, then we can block the user's books from showing up, etc. and if not, then it just functions as `getBooksNoToken`