Create long living JWTs when login in from mobile apps

[joergreichert]

State of the art:
Users are required to login again and again when opening the LeipzigGiesst

Motivation:
Remembering, accessing and enter the credentials (non-techies may not use a password manager or just hit the password reset function) is tedious and may hinder users to use the app frequently, thus the need to login should be reduced to a minimum

Future state:
Web-app detects that is opened within a mobile app and requests a long lived JWT (1 year or infinite), that is stored at the mobile phone