On Windows, os::FileDialogWin32::showWithNewAPI() should launch another process exclusively to open the native file dialog as we've received several crash reports just because buggy IMEs (#4150)

If we're going to implement the native IME support on Windows (#2841) this will be an huge problem for us (receiving crash report for any text field). So in this case, and if it's possible, the IME should be opened from a background process just to avoid crashing the main process.

EDIT: We've received reports (internal ticket 6346) where just opening the native file dialog crashes/closes Discord. Switching back to our file selector fixed the issue (🤔)