GBDK offers a variety of util functions, meaning that many game boy functions can be used without having to re-invent the wheel in rust-gb.

However, since GBDK is a C library, we need to make sure which part to use and not. For example, gprint and gprintn can be safely wrapped and used, but gprintf will need to be replaced by fmt.
Also, some things need to change shape. I want to avoid global status management like color as much as possible.

This milestone's goal is that checks these points, determines which GBDK functions to provide, and provides a safe wrapping or replacement Rust implementations.