Configure MinGW to consume Vista+ APIs

[janisozaur]

This is proof of concept and may require some discussion. This effectively drops XP support we've sort-of had until now, even though we claimed we don't have it.

[LRFLEW]

Would it work to put these defines in CMakeLists_mingw.txt? It might be cleaner to do it that way if it makes sense.

[janisozaur]

@LRFLEW I'm not sure if this would have to go into CMakeLists.txt or can it be in CMakeLists_mingw.txt. The current way is just a tiny bit easier and more contained, but we can do that with CMake as well.

[IntelOrca]

Visual Studio can still compile for XP using these APIs, but I am not sure what happens when executed.

[LRFLEW]

BTW, something weird happened involving this PR that caused the CI build to be pushed to openrct2.org. The build (in theory) shouldn't be any different from the previous one, so I'm not so worried about the API pulling the wrong build as the "current" one, but it is worth noting that it happened.

https://openrct2.org/downloads/develop/e67d54c

[IntelOrca]

@LRFLEW its because @janisozaur pushed the branch to the main repo rather than his fork.

[janisozaur]

it still shouldn't push to .org, I'll have to check that

[IntelOrca]

I thought we made it so that it only pushed it .org if it begins with push/

[janisozaur]

I thought so too, but there must be a bug in the guard I made.