Multiloader port (fabric/neo)

[AndreAugustoDev]

I used https://github.com/jaredlll08/MultiLoader-Template as base The build scripts were rewritten in Kotlin DSL.

Since code does not use anything loader specific, its simple to move to a 'common' approach Only 2 mixins needed to be written per loader due to different targets between loaders.

The configuration file and menu is the same in both loaders.

I also changed mappings to Mojmaps, but if you want I can study a way to keep Yarn mappings