Refactor account token verification #89
Description
Currently the account token is verified with every followed link or page refresh in App.vue. In detail using a Promise, the account token is read from localStorage, checked for expiration date and with a subsequent Promise checked for validity against the gin-auth server. Only then the session is restored and the user account is properly set for all child components.
This leads to problems when child components, that rely on an account being present, are set up at the same time. This in turn leads to race conditions between the main App and the child components often resulting in Errors or missing information when the displaying the current page.
Therefore the current token verification process should be refactored to ensure no race conditions with child components can occur.