Added a method to get the internal viewport of a PropertyPanel

modules/juce_gui_basics/properties/juce_PropertyPanel.h

@@ -149,6 +149,10 @@ public:
     */
     const String& getMessageWhenEmpty() const noexcept;
 
+    //==============================================================================
+    /** Returns the PropertyPanel's internal Viewport. */
+    Viewport& getViewport() noexcept        { return viewport; }
+
     //==============================================================================
     /** @internal */
     void paint (Graphics&) override;