kstyle: add left padding to menus in the 'no checkboxes or icons' case

This improves the appearance by avoiding having text near directly against a border.

kstyle/breezemetrics.h

@@ -50,6 +50,7 @@ namespace Breeze
         // menu items
         static constexpr int Menu_FrameWidth = 0;
         static constexpr int MenuItem_MarginWidth = 8;
+        static constexpr int MenuItem_ExtraLeftMargin = 4;
         static constexpr int MenuItem_MarginHeight = 4;
         static constexpr int MenuItem_ItemSpacing = 4;
         static constexpr int MenuItem_SeparatorPadding = 0;

kstyle/breezestyle.cpp

@@ -4887,6 +4887,8 @@ namespace Breeze
             contentsRect.setLeft( iconRect.right() + Metrics::MenuItem_ItemSpacing + 1 );
             const QSize iconSize( pixelMetric( PM_SmallIconSize, option, widget ), pixelMetric( PM_SmallIconSize, option, widget ) );
             iconRect = centerRect( iconRect, iconSize );
+        } else {
+            contentsRect.setLeft( contentsRect.left() + Metrics::MenuItem_ExtraLeftMargin );
         }
 
         if( showIcon && !menuItemOption->icon.isNull() )