First release on 1.21

First release on 1.21, and ported to neoforge in replacement of forge.

Completely re-wrote EVERYTHING to use proper packets and networking, and also refactored to a multi-loader setup instead of independent projects.

Completely re-wrote EVERYTHING to use proper packets and networking, and also refactored to a multi-loader setup instead of independent projects.

Fixed "Activated pack" message when actually de-activating a pack to be "Deactivated pack"