Fix issues with UpdateTrackers.

Added an Update tracker. You can assign a functional interface server-side, and it'll run that every tick.

Make minor changes to libMCdev Media, and rewrite the camera system fully.

Probably more, but I can't be bothered to list the non-parity breaking stuff here for a release that will be overshadowed soon

Remove the rest of the camera system, as it semi-breaks spectator mode as of now.

Fix a 1.20.2 issue, and also fix the build system for libMCdev. (Yay! Sources, and working versioning!)