feature/login

[paulrichter99]

Providing the logic behind User login containing:

• login screen login
• header change with profile tab when logged in
• authToken system (not having to login every time)

This is mandatory for feature/events since we need users to ensure you only see/edit/create events for yourself

[paulrichter99]

Done with commit 94c057b46501d6ab318b257f4728e8b53979629e