Make Mapillary feature more user-friendly

[UJehle]

The map is a bit disturbing when looking at the Mapillary pictures. Would be nice, if the map could be moved (e.g. to the bottom) or the size decreased.

Furthermore, it is only possible to open pictures from a sequence in the map when you zoom in really close. Would be nice if this would also be possible with a lower zoom. If not then we should maybe provide a hint for the user.