Add a feature to the CookieTransport class to redirect to a specific URL after login. This is useful because currently, a user won't be redirected after logging in via OAuth and will be stuck on the OAuth server's "redirecting"/"successfully logged in" page.

The current fix for this issue is to create another CookieTransport class and overwrite the get_login_response function like this:

class RedirectingCookieTransport(CookieTransport):
    async def get_login_response(self, token: str) -> Response:
        response = RedirectResponse(redirect_url, status_code=status.HTTP_302_FOUND)
        return self._set_login_cookie(response, token)

Though I think that this should just be a feature of the library.