[WIP] Draw real geometry of public transit line

[InterStella0]

This PR attempted to implement #1743. The routes that are given by shapes.txt can be inferred even when you don't have shape_dist_traveled via haversine formula or point from line formula.

Sample Output:

Thoughts & Problems

1. Once I've generated the polyline, should it be set onto PtLeg.geometry or a new attribute?
   • I replaced geometry with a multi line string instead
2. There are times when the routes completely disappear, I assume this is due to routes missing/unmatched, should this be replaced with a single line from/to stops?
3. Sometimes the path of point A to point B is a bit far from the closest stop, thus creating an "incomplete" polyline, I guess a way to fix this is to artificially create a point closest to stop relative to the direction of A to B.

• Example of incomplete polyline: