Car Classes, Class Rankings & UI Improvements

Added car classes and class-based rankings across the Competition system.

You can now filter and browse results by class throughout the site, with categories like Street, Track, GT, Prototype, Open Wheel, Rally and Classic.

So your 10-minute vintage car lap no longer has to be scared of a 1-minute modern spaceship lap. 😄

I also made a few UI improvements across the site to keep things cleaner and easier to use.

The system is still being tested, so feedback is always welcome.