Restore separator spacing in context menus

This restores the spacing for separators that was lost since around
Plasma 5.20.

Long menus can be difficult to scan and overwhelming when all items are
clumped together with no additional spacing. This balances the
margins/padding similar to how they were pre-5.20.

kstyle/breezemetrics.h

@@ -50,11 +50,11 @@ namespace Breeze
 
         // menu items
         static constexpr int Menu_FrameWidth = 0;
-        static constexpr int MenuItem_MarginWidth = 8;
+        static constexpr int MenuItem_MarginWidth = 5;
         static constexpr int MenuItem_ExtraLeftMargin = 4;
-        static constexpr int MenuItem_MarginHeight = 4;
+        static constexpr int MenuItem_MarginHeight = 3;
         static constexpr int MenuItem_ItemSpacing = 4;
-        static constexpr int MenuItem_SeparatorPadding = 0;
+        static constexpr int MenuItem_SeparatorPadding = 3;
         static constexpr int MenuItem_AcceleratorSpace = 16;
         static constexpr int MenuButton_IndicatorWidth = 20;