Initial CMake, Windows 98 SE(???) is working again, PSP Compiling and Linking Again (Not Running), CI included

[playmer]

(This was initially just a PSP PR, but I've evolved the branch enough to get XP Windows 98 SE(???) working with the CMake builds, so I figured I might as well PR that too.)

I know there's been concern about breaking previous in-source ports, so before I suggest more interesting changes I wanted to get some of them working again.

• Windows XP support works again. I'm building all of the old dependencies except for SDL inside of the CMake, and did an initial trim down to slim down the binary size. This will need some tire kicking, and it's possible we can slim down further. I'm punting on building SDL inside of the CMake as it's a little more onerous than the other dependencies given how so many subsystems are platform dependent. Plus we can't really slim it down much further, at least at first glance.
• Initial work towards PSP support was added before getting Windows XP running again, but now that we have that, XP is obviously the star of the show. It's still not producing usable EBOOTs, but it's a step in the right direction. I'll need to look in how to actually package the executable with a game and test it out. Ideally we could have the CI run a simple script and ensure it doesn't crash,, but we're not there yet.

The CMake is still messy, please excuse it, I'll be continuing to iterate on it as time goes on so it can target more platforms (Mac will be up next).

[playmer]

Given the other PRs in flight are based on this one, I'm throwing this back to draft so I can rebase it once they're merged. I also have one more incoming regarding the simd accelerated graphics functions that was discussed a couple months ago. Hope to make a PR later this week.