Stats overlay for video player

[eden881]

This PR adds a minimal stats overlay using data already extracted from video frames.
Live demo: https://tesla-dash.eden881.dev/

• Shows current speed, gear, steering wheel position, brake and accelerator pedal status, and Autopilot status
• Toggle km/h and mph by clicking the current speed
• Accelerator pedal indicator fills to show the amount pressed, like the in-car UI
• Works well with smaller screen widths too