Request new license token if old one is expired.

If the license token expires, a new token should be accquired with the {{refreshUrl}} claim in the old token.
Two strategies are possible:

* automatic: Use polling or a predefined trigger to get new token
* manual: Show a refresh button in the billing component

Of course, the first is the desirable way, increasing UX by not forcing the user to act and keeping it convenient.

Remark: The {{refreshUrl}} must be called in backend due to CORS restrictions in frontend.