fix: add new logic to junction post converter

this fix adds a new logic to junction post converter.
in the new logic, if a road leads to a junction, the successor of lanes in this road can be duduced from junction internal data.

details:

1. The junction converter will go through each junction connection.
2. Then junction connection will read each junction lane link.
3. The converter is then able to use the following logic to deduce successor of a lane:
   1. if junction_lane_link.from < 0 && junction_lane_link.to < 0, this means the incoming road's last lane section will connect to start section of the connecting road.
   2. if junction_lane_link.from < 0 && junction_lane_link.to > 0, this means the incoming road's last lane section will connect to last section of the connecting road.
   3. if junction_lane_link.from < 0 && junction_lane_link.to < 0, this means the incoming road's start lane section will connect to start section of the connecting road.
   4. if junction_lane_link.from < 0 && junction_lane_link.to > 0, this means the incoming road's start lane section will connect to last section of the connecting road.