add max-height and scroll to domain dropdown

src/app/shared/common/domainfilter/domainfilter.component.css

@@ -22,4 +22,9 @@
                 padding-bottom: 10px !important;
                 line-height: 20px !important;
         }
+
+        .dropdown-menu {
+                max-height: 500px;
+                overflow-y: auto;
+        }
 }
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