feat: Support for C and perhaps other languages too

[eliassjogreen]

It would be nice to have support for more languages than just rust, but I understand if that is out of the scope of the project at the moment. Anyways I propose splitting up codegen into a different crate and removing serde instead opting for encoding and decoding repr(C) objects in js directly using the new UnsafePointerView (wrote a small prototype in ts to prove that this works which it does).

This approach would let us continue using the macro for rust, and possibly reusing the codegen for analyzing other languages such as C header files while being more intuitive and most likely performant.