Store location to improve user experience on map landing

[ronw98]

When the user lands on the map, the map is centered on paris.

The goal of this ticket is to store and use the last known coordinates to center the map on these coordinates instead of paris.

Depends on #11 to be finished

[BriceCroix]

geolocator provides at method Geolocator.getLastKnownPosition() to do this, we have to add this to datasource, repository, and use-case.