Yellow squiggly lines begone!
Done automatically on .cpp files through `run-clang-tidy`, with manual corrections to the mistakes.
If an import is directly used, but is technically unnecessary since it's recursively imported by something else, it is *not* removed.
The tool doesn't touch .h files, so I did some of them by hand while fixing errors due to old recursive imports.
Not everything is removed, but the cleanup should be substantial enough.
Because this done on Linux, code that isn't used on it is mostly untouched.
(Hopefully no open PR is depending on these imports...)

UnitTests: Replace ties with structured bindings

Fixes LIT (https://bugs.dolphin-emu.org/issues/13635). The text does not include normals, but has lighting enabled. With the previous default of (0, 0, 0), lighting was always black (as dot(X, (0, 0, 0)) is always 0). It seems like the normal from the map in the background (0, 0, 1) is re-used.

LIT also has the vertex color enabled while vertex color is not specified, the same as SMS's debug cubes; the default MissingColorValue GameINI value of solid white seems to work correctly in this case.

Replace boolean constants with boolean literals