fix(visualization): add proper spacing between secondary metrics table rows

Replace ineffective padding-top on table rows with border-spacing on table element, as padding does not work on display: table-row elements.

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Co-Authored-By: Claude <noreply@anthropic.com>

Author: christian-huehn-mw

visualization/app/codeCharta/ui/attributeSideBar/attributeSideBarSecondaryMetrics/attributeSideBarSecondaryMetrics.component.scss

@@ -13,4 +13,9 @@
         height: 100%;
         padding-top: 12px;
     }
+
+    .secondary-metrics {
+        border-spacing: 0 2px;
+        border-collapse: separate;
+    }
 }