#14203 Add cumulative curve option to Grid Statistics plot

A new "Show Cumulative Curve" checkbox on the grid statistics data source adds a cumulative curve on the right axis, in addition to the regular histogram curve. The cumulative curve shares the data source of its non-cumulative counterpart and follows all changes to it. The cumulative sum works with all frequency types and both graph types.

Remove the legacy Grid Statistics dialog (RicGridStatisticsDialog) and its context menu command, which provided the previous cumulative display.

ApplicationLibCode/UserInterface/RiuViewerCommands.cpp

@@ -660,7 +660,6 @@ void RiuViewerCommands::displayContextMenu( QMouseEvent* event )
         {
             menuBuilder.addSeparator();
             menuBuilder << "RicCreateGridStatisticsPlotFeature";
-            menuBuilder << "RicShowGridStatisticsFeature";
             // Grid statistics commands operate on the result shown in the overlay info box, so only
             // offer them when the context menu is invoked inside that box, not on the view geometry.
             if ( m_viewer->isMousePosWithinInfoBox( event->x(), event->y() ) )