Add new checkpoint colors for new laps

This PR adds new checkpoint colors for the finish line and replaces the default color.

New color key:

* Normal checkpoint: green
* Finish line, new lap: cyan
* Finish line, last lap ahead (only in races with lap limit): blue
* Finish line, ends race (only in races with lap limit): red

I tested it myself and it seems to work. There is 1 FIXME in the code, please check if that line is the proper way to find out wheather the game uses laps or not.