Get GPS and ride mode from backend

[nschoen]

Description: Repeatedly receive the GPS position of the car from the backend to display the current route in the app. Additionally react to informations regarding the route (e.g. final destination) to know when the shift actually ends and when not.

Acceptance criteria:

• [ ] Receives GPS data from the backend
• [ ] Updates GPS data in the turn-by-turn view
• [ ] Reacts to route/shift mode changes

[nschoen]

Closed, out of scope.