Add Switch platform

[halotroop2288]

This implements the changes required to build the Nintendo Switch platform, using a submodule maintained by the Homebrodot team.

This fork will keep track of changes needed for Homebrew platforms such as the Switch and Vita.

[halotroop2288]

Dunno why you cancelled the Windows one but everything else seems to be passing.

[Relintai]

I have slept on this.

Modularity

All Switch specific stuff should reside in it's own platform folder, for lots of reasons, including maintainibility, and modularity. Actually I have been moving away from using the thirdparty directory for years now. Also Nintendo is scary.

Submodules

As I said on discord, I have no intention of using git submodules, I have already got bitten really hard by them. After that I evaluated all alternatives, and eventually I ended up just rolling my own solution. I didn't just do it to show off or something like that. Every alternative turned out to be a pain if you want them to work on multiple platforms (especially if we include all the dependency management stuff, scoop, msys2, brew, containers etc.).

Also since then I realized that a platform like this it extremely nieche, so even having dependency management for it is probably unnecessary.

Also: Even if Nintendo wasn't scary, the engine itself needs to be free of any code of potential issue anyway.

Conclusion

I think it would be unfair to expect these types of changes from you, also I really want to see Broken Seals run on my old switch just for the cool factor, so I think I'll pull an "Uno reverse card meme" on this, and will probably do these and pr the changes to you instead. (After the license is sorted out in the platform's repository. (I already got burned by not paying attention to licensing recently. See: https://github.com/Relintai/smtp_node and 8e5ffcc and then https://github.com/Relintai/pandemonium_engine/commits/master/modules/smtp )))

Also sorry if I come off as annoying and/or nitpicky, but getting architectural things right is the hardest and (in my experience so far) it's the most important thing to get right in modern software development, so I take a lot more care in changes like these.