eliminate unnecessary uses of octave_qobject in GUI classes * BaseControl.cc, BaseControl.h, ButtonControl.cc, ButtonControl.h, ButtonGroup.cc, ButtonGroup.h, Canvas.cc, Canvas.h, CheckBoxControl.cc, CheckBoxControl.h, Container.cc, Container.h, ContextMenu.cc, ContextMenu.h, EditControl.cc, EditControl.h, Figure.cc, Figure.h, GLCanvas.cc, GLCanvas.h, ListBoxControl.cc, ListBoxControl.h, Menu.cc, Menu.h, Object.cc, Object.h, Panel.cc, Panel.h, PopupMenuControl.cc, PopupMenuControl.h, PushButtonControl.cc, PushButtonControl.h, PushTool.cc, PushTool.h, RadioButtonControl.cc, RadioButtonControl.h, SliderControl.cc, SliderControl.h, Table.cc, Table.h, TextControl.cc, TextControl.h, ToggleButtonControl.cc, ToggleButtonControl.h, ToggleTool.cc, ToggleTool.h, ToolBar.cc, ToolBar.h, ToolBarButton.cc, ToolBarButton.h, annotation-dialog.cc, annotation-dialog.h, qt-graphics-toolkit.cc, qt-graphics-toolkit.h, command-widget.h, community-news.cc, community-news.h, documentation-bookmarks.cc, documentation-bookmarks.h, documentation.cc, external-editor-interface.cc, external-editor-interface.h, find-files-dialog.cc, find-files-dialog.h, graphics-init.cc, graphics-init.h, interpreter-qobject.cc, file-editor.cc, find-dialog.cc, find-dialog.h, main-window.cc, main-window.h, news-reader.cc, news-reader.h, octave-qobject.cc, release-notes.cc, resource-manager.cc, set-path-dialog.cc, set-path-dialog.h, shortcut-manager.cc, shortcut-manager.h, welcome-wizard.cc, welcome-wizard.h, workspace-model.cc: Don't store references to octave_qobject in GUI classes where it is no longer needed. Eliminate unnecessary octave_qobject constructor arguments. Change all uses.

--- a/libgui/graphics/Container.h	Sun Dec 04 22:56:23 2022 -0500
+++ b/libgui/graphics/Container.h	Sun Dec 04 22:57:02 2022 -0500
@@ -35,11 +35,6 @@
 
 namespace octave
 {
-  class base_qobject;
-}
-
-namespace octave
-{
 
   DECLARE_GENERICEVENTNOTIFY_SENDER(ContainerBase, QWidget);
 
@@ -50,8 +45,7 @@
     Q_OBJECT
 
   public:
-    Container (QWidget *parent, octave::base_qobject& oct_qobj,
-               octave::interpreter& interp);
+    Container (QWidget *parent, octave::interpreter& interp);
     ~Container (void);
 
     Canvas * canvas (const graphics_handle& handle, bool create = true);
@@ -81,7 +75,6 @@
     void resizeEvent (QResizeEvent *event);
 
   private:
-    octave::base_qobject& m_octave_qobj;
     octave::interpreter& m_interpreter;
     Canvas *m_canvas;
   };