Fixes a macOS Metal crash when stopping immediately after boot starts.

m_upload_encoder and m_texture_upload_encoder could be dealloc'd during shutdown before endEncoding could be called, which causes a Metal assertion failure.

Co-authored-by: OatmealDome <julian@oatmealdome.me>

DX, OGL: fix assert

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...)

Fix various typos and spelling mistakes

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

Move the constructor and destructor after the definition of the class
`Internal`.

This fixes an error generated by Clang from the destructor of
`std::unique_ptr<Internal>` when setting the standard version to c++23:

`invalid application of 'sizeof' to an incomplete type 'Metal::ObjectCache::Internal'`.