Update Qt Advanced Docking System to the parent-preservation fix cherry-picked onto CeetronSolutions master. Keep inactive docks hidden under the dock manager instead of temporarily making them top-level windows, avoiding disruption of QOpenGLWidget composition without enabling native windows.
Related to #14714. ADS fix cherry-picked from kriben/Qt-Advanced-Docking-System commit 7d6f2e71e374b95d600467602b770a8c8cf85d07.