Add a "refresh token automatically" function

[JasonLaw1994]

Right now, we check whether we should refresh token or not when "loading", but this can cause a problem.

For example, if "loading" happen at 15 minutes before access token is expired, we don't refresh token (we refresh token 10 minutes before expiration). If I stay at the website for more than 15 minutes, the access token will be expired. Of course, the user can refresh token by reloading page, but I think it's better if the application can refresh token automatically when it find out that the access token is expired.