Add global notification area and use for UI Tour info

Adds a global info bar display above the main window's status bar that
can be accessed via ICore::infoBar().

Replace the blocking "Take UI Tour" dialog by a notification there.

Fixes: QTCREATORBUG-22819
Change-Id: I733f1bfd2d1db0295754ed2e28bb202f927d0edb
Reviewed-by: hjk <hjk@qt.io>
Reviewed-by: André Hartmann <aha_1980@gmx.de>

src/plugins/coreplugin/fancytabwidget.h

@@ -25,6 +25,8 @@
 
 #pragma once
 
+#include "infobar.h"
+
 #include <QIcon>
 #include <QWidget>
 
@@ -157,6 +159,7 @@ public:
 
     int currentIndex() const;
     QStatusBar *statusBar() const;
+    InfoBar *infoBar();
 
     void setTabEnabled(int index, bool enable);
     bool isTabEnabled(int index) const;
@@ -183,6 +186,8 @@ private:
     QStackedLayout *m_modesStack;
     QWidget *m_selectionWidget;
     QStatusBar *m_statusBar;
+    InfoBarDisplay m_infoBarDisplay;
+    InfoBar m_infoBar;
 };
 
 } // namespace Internal