Reimplement devkitPro tools within cargo-3ds

[Meziu]

Having dependencies on third party tools that must be in range of the environment commands isn't a good idea. Also, smdhtool isn't designed very well, and misses some features. Rewriting the tools in Rust, in the form of libraries for the main binary, would be the best approach, but it will take quite some time.

[Maccraft123]

Hey, so the other day I made a Rust library that could make this possible if it gets more support for creating files and not just reading them, currently, out of creating files it only supports making FIRM files, but it could be extended to support making other files. Note that SMDH image format is very annoying to work with and it has been shelved temporarily.

https://github.com/Maccraft123/cytryna/

[Meziu]

Wow, that's some very interesting work! Please update us if you manage to write valid .smdh files, as we could really gain from your contributions.

This could also open the door for .cia or other formats, but I'd like to keep it simple for now.

[Maccraft123]

Please update us if you manage to write valid .smdh files

Done, already had it on mind for a while so I just grabbed some code that i shelved
Maccraft123/cytryna@d97cde5