add point_hints to route request

[karussell]

The coordinate snaps to the closest point on a street but sometimes this is not the right street. When we have an address we should use the street as the point_hint to improve the snapping.

Todo: we need to put this information into the URL state. As the street name is often already part of the text this would increase the URL length unnecessarily. But we could use a placeholder like <s> for the text (?) and use a third entry ala coord_text_street (currently we use only two coord_text).