Fixed the collapsed block popup to draw on top of cursor/highlights

The various text editor overlays and the text cursor were being painted
on top of the collapsed block popup.

Reviewed-by: mae

src/plugins/texteditor/basetexteditor.h

@@ -487,6 +487,11 @@ private:
                            bool active,
                            bool hovered) const;
 
+    void drawCollapsedBlockPopup(QPainter &painter,
+                                 const QTextBlock &block,
+                                 QPointF offset,
+                                 const QRect &clip);
+
     void toggleBlockVisible(const QTextBlock &block);
     QRect collapseBox();