Update class-tweaker to be usable today

[Earthcomputer]

Updated class-tweaker to hopefully be usable in fabric loader and loom in 2025. This would have the advantage of being able to specify injected interfaces in a class tweaker file (currently the access widener file), and in named mappings rather than in intermediary file in a somewhat random location (the FMJ).

• Updated the buildscript
• Removed enum extensions. It is hoped that these can be re-added later with an improved design. But removing them now means we can use class-tweaker for its other benefits.
• Updated interface injection to do all the extra stuff it now does in loom, notably including generics.

[modmuss50]

Looks great. Hopefully what was here isnt too much of a mess to start with.

Just thinking regarding the iface injection does there need to be a way for them not not be applied at runtime? As this is something Mixin will handle.