[ENH] Distance round lap as basis for delta_time

[psychemedia]

Proposed new feature or change:

Looking at the utils.delta_time, it appears to be making comparisons based on the distance travelled by each vehicle? Might a better comparison be to model a single racing line trajectory around the circuit, and then map the lat-long co-ords at each point onto that line to calculate a normalised "distance round track" measure?

In shapely, I think this is how you can project a point onto a route (eg the centreline of the circuit):

def map_point_to_route(point, route):
    return route.geometry.interpolate(route.geometry.project(point))

The distance along the route is then route.geometry.project(end_point) - route.geometry.project(start_point)