Fixed the cursor follow issue on Windows. The code looks simple and clear enough to submit, but I don’t know how to deal with combo problems.

[Q191]

IME is the main problem for cjk users in many opengl guis.

IME problem means unusable, for examples: fyne go-flutter, but gioui seems works.

Hope someone finally fix this.

[GGRei]

Thanks for working on this. Before merging, a few points still need to be corrected:

• COMPOSITIONFORM must use the exact Win32 layout with an inline RECT, the caret coordinates need proper DPI conversion.
• The HWND should be kept separate from the vglyph overlay handle, and the duplicate positioning path and debug output should be removed.
• The modified files also need formatting (v fmt).