feat(obfuscator/transformers): Mixin Remapper

[Trol]

I'm not sure if the code quality is up to the standards expected, probably have missed some code requirements / formatting stuff, so yeah.

This is an initial Mixin Remapper implementation, which only supports class remapping.

"MixinTransformer" has some // TODO's, which I probably need a discussion on, so feel free to point those out and let me know on how I should proceed.

Needs further testing with a working Remapper inplace, which for Mixin classes it would only obfuscate their class names. (Cannot do that yet, would be appreciated if someone could see if this works at all, or I did something dumb :()

Ideally, I would like to also implement:

• Field Remapping
• Method Remapping
• Renaming the Mixin config json would work, but that would require remapping any class that contains references to the config json or changing it within specific mod loader's json. * Probably providing the type of (legacy)fabric/fml (post 1.12)/neoforge/custom , where custom -> Tweaker implementation or manually initialized")
• Support remapping of plugins implementing "IMixinConfigPlugin"