Adds a css class for mr reports to render them correctly

app/assets/javascripts/reports/components/grouped_test_reports_app.vue

@@ -82,7 +82,7 @@
     :loading-text="groupedSummaryText"
     :error-text="groupedSummaryText"
     :has-issues="reports.length > 0"
-    class="mr-widget-border-top grouped-security-reports"
+    class="mr-widget-border-top grouped-security-reports mr-report"
   >
     <div
       slot="body"

app/assets/stylesheets/pages/merge_requests.scss

@@ -87,7 +87,7 @@
     padding: 0;
   }
 
-  .grouped-security-reports {
+  .mr-report {
     padding: 0;
 
     > .media {