winex11: Retrieve the whole window when creating client window for other process.
As soon as x11drv window data has been created, X11DRV_get_whole_window will return it instead of looking up the whole window from the window property.
Wine-Bug: https://bugs.winehq.org/show_bug.cgi?id=59091 Wine-Bug: https://bugs.winehq.org/show_bug.cgi?id=59094