Rotate map based on the place you are coming from and going to + mode of transport

[KasperZutterman]

How can we find the optimal rotation angle for the map?
Rotating the map view should result in a view where you enter the city on the bottom, like how a GPS view is centered.

• As a first step, we could use the bearing angle: https://stackoverflow.com/questions/3932502/calculate-angle-between-two-latitude-longitude-points
• Then based on the selected mode of transport we could make use of a route planner to see the closest matching angle of entering the city

[KasperZutterman]

See #19 for the first part of the implementation