Regression test fixes (#9068)

* Make sure font size is updated correctly
* Hide empty sub titles
* Do not categorize as water cut if no curves are visible
* Propagate settings from single summary plot to summary multi plot

ApplicationLibCode/UserInterface/RiuAbstractOverlayContentFrame.h

@@ -31,6 +31,9 @@ public:
     ~RiuAbstractOverlayContentFrame() override;
 
     virtual void renderTo( QPainter* painter, const QRect& targetRect ) = 0;
+
+protected:
+    void updateFontSize();
 };
 
 class RiuTextOverlayContentFrame : public RiuAbstractOverlayContentFrame
@@ -42,6 +45,9 @@ public:
     void setText( const QString& text );
     void renderTo( QPainter* painter, const QRect& targetRect ) override;
 
+private:
+    void updateLabelFont();
+
 private:
     QPointer<QLabel> m_textLabel;
 };