benchmark_toolbox: reorganize tabs

Source/Benchmark-Toolbox/lib/borealis/library/include/borealis/views/sidebar.hpp

@@ -84,6 +84,11 @@ class Sidebar : public ScrollingFrame
      */
     void addItem(std::string label, GenericEvent::Callback focusCallback);
 
+    /**
+     * Adds a non-focusable section header to this sidebar.
+     */
+    void addHeader(std::string label);
+
     /**
      * Adds a separator to this sidebar.
      */

Source/Benchmark-Toolbox/lib/borealis/library/include/borealis/views/tab_frame.hpp

@@ -37,6 +37,7 @@ class TabFrame : public AppletFrame
     void handleXMLElement(tinyxml2::XMLElement* element) override;
 
     void addTab(std::string label, TabViewCreator creator);
+    void addHeader(std::string label);
     void addSeparator();
 
     static View* create();