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/src/community-news.h	Sun Dec 04 22:56:23 2022 -0500
+++ b/libgui/src/community-news.h	Sun Dec 04 22:57:02 2022 -0500
@@ -33,17 +33,15 @@
 
 namespace octave
 {
-  class base_qobject;
-
   class community_news : public QWidget
   {
     Q_OBJECT
 
   public:
 
-    community_news (base_qobject& oct_qobj, int serial);
+    community_news (int serial);
 
-    community_news (base_qobject& oct_qobj, QWidget *parent = nullptr,
+    community_news (QWidget *parent = nullptr,
                     const QString& base_url = "https://octave.org",
                     const QString& page = "community-news.html",
                     int serial = -1);
@@ -58,8 +56,7 @@
 
   private:
 
-    void construct (base_qobject& oct_qobj, const QString& base_url,
-                    const QString& page, int serial);
+    void construct (const QString& base_url, const QString& page, int serial);
 
     QTextBrowser *m_browser;
   };