std.os.windows additions and fixes

[Szwagi]

This pull request addresses issues I have found with std.os.windows while using it.

std.os.windows

• Added PROC type
• Added HRESULT_CODE macro

std.os.windows.opengl32 (new)

• Moved wglCreateContext from gdi32
• Moved wglMakeCurrent from gdi32
• Fixed wglCreateContext using incorrect types
• Fixed wglMakeCurrent using incorrect types
• Added zig wrapper for wglCreateContext
• Added zig wrapper for wglMakeCurrent
• Added wglDeleteContext + zig wrapper
• Added wglGetProcAddress

std.os.windows.dwmapi (new)

• Added DwmFlush + zig wrapper

std.os.windows.gdi32

• Added constants required for PIXELFORMATDESCRIPTOR
• Fixed SetPixelFormat using incorrect types
• Added zig wrapper for SetPixelFormat
• Fixed ChoosePixelFormat using incorrect types
• Added zig wrapper for ChoosePixelFormat
• Added DescribePixelFormat + zig wrapper
• Moved wglCreateContext and wglMakeCurrent to opengl32
• Fixed SwapBuffers using incorrect types
• Added zig wrapper for SwapBuffers

std.os.windows.kernel32

• Fixed GetFileAttributesW using incorrect types ([*]const WCHAR instead of [*:0]const WCHAR)
• Fixed GetProcAddress using incorrect types ([*]const u8 instead of [*:0]const u8)

std.os.windows.user32

• Added WaitMessage + zig wrapper
• Added MsgWaitForMultipleObjects + zig wrapper
• Added GetQueueStatus
• Added QS_* constants
• Added MINMAXINFO struct
• Added SetPropA + zig wrapper
• Added SetPropW + zig wrapper
• Added GetPropA
• Added GetPropW
• Added GetClientRect + zig wrapper
• Added GetWindowRect + zig wrapper
• Added SetWindowPos + zig wrapper
• Added SWP_* constants
• Added HWND_* constants
• Added LoadCursorA + zig wrapper
• Added LoadCursorW + zig wrapper
• Added IDC_* cursor constants
• Added GetSystemMetrics
• Added GetSystemMetricsForDpi + zig wrapper
• Added SM_* constants
• Added ARW_* constants
• Added NID_* constants

I am unsure about the names for opengl32 zig wrappers. The convention seems to be using lowercase, but wgl* functions are already lowercase, so I added a "Z" at the end for now. Perhaps removing the wgl prefix and using lowercase is the way to go?

I am also unsure about the IDC_ constants. In C they are casted into the correct type (LPCSTR, LPCWSTR) depending on the defined character set. Currently passing them to LoadCursor* requires @ptrFromInt(IDC_*).

Note that I am an on-and-off unexperienced Zig user, and a first time contributor, so I hope I didn't butcher any of the syntax.

[squeek502]

Just a heads up: the fixes are much more likely to be merged than the additions, unless there's a use-case within the standard library or the Zig compiler source code.

Relevant issues:

• reduce windows API bindings in the standard library to the minimum required for the standard library's own abstractions to work #4426
• Prefer depending on NtDll rather than kernel32 or other higher level DLLs #1840

Note also that the added bindings do not have to be part of the standard library for you to be able to use them. They can go in your project's source and it'll work just fine.

EDIT: Personally, I think it might make sense for Zig's standard library to contain definitions for all types that are defined using opaque{} to allow for interoperability, though.

[squeek502]

With user32.zig getting deleted in #17763, I think the best way forward would be to trim this down to just windows.zig additions/kernel32.zig fixes.