Wrong monolane for an intersection between an arc and a segment

[basicNew]

Test to reproduce:

    def broken_intersection_on_one_lane_city(self):
        """
                      (0,50)
                        |
                        |    __--- (50,20)
        (-50,0) ------- + ---
                        |
                        |
                      (0,-50)
        """
        city = City("Broken intersection - One lane")

        s1 = Street.from_control_points([Point(-50, 0), Point(0, 0), Point(50, 20)])
        s1.name = "s1"

        s2 = Street.from_control_points([Point(0, -50), Point(0, 0), Point(0, 50)])
        s2.name = "s2"

        city.add_intersection_at(Point(0, 0))

        city.add_road(s1)
        city.add_road(s2)

        return city

Generated monolane

The problem is most likely due to the fact we compute the arcs endpoints based on the length from the intersection points to some given offset over the lanes. However it is not the same to consider the length in a straight live vs the length over an arc (as is the case on an intersection that includes non-collinear segments).