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...)

Requires at least GCC 11, Clang 13, MSVC 19.30 (VS2022 17.0), or AppleClang 13.1.6 (XCode 13.3).

Mirrors the C++23 <utility> function, std::to_underlying

We need to copy padding in most of these cases, and the objects are trivially copyable; however, BitField prevents trivial copy-assignment.

Rather than makring some parts of VertexLoaderManager dirty in some places and some in others, do it all in VideoState. Also, since CPState no longer contains pointers/non-CP data after d039b1bc0dfaba2a88036468b6d971bb1d7e463d, we can just use p.Do on it instead of manually saving each field.