Move to use `CsWin32` for `System.Drawing.Common` interop

[elachlan]

Tracking issue for migrating System.Drawing.Common to use CsWin32.

Related:

• Gdiplus missing some functions/enums GdipCreateSolidFill, GdipCloneBrush, GpStatus microsoft/win32metadata#1287
• Initial support for GDI+ microsoft/win32metadata#1709

[elachlan]

@JeremyKuhne I remember seeing a PR about versioning on System.Drawing.Common. Its a bit different from Winforms in that is supports multiple .NET versions in the one project instead of branches. Will this be changing? I am unsure how I should approach it with CsWin32.

[JeremyKuhne]

@elachlan It will always support multiple versions. I don't think that will matter for usage of CsWin32 as we can use it for all the supported platforms, which for .NET 9 will be building sources for .NET 8 & 9 (see the project file only includes the sources for .NETCoreApp).

[elachlan]

Related: #9863

[elachlan]

@JeremyKuhne for code that we want to share between interop projects, do we place them in src\Common\src? or should we create a sub folder interop?

[elachlan]

@JeremyKuhne I think this is done?