[refactor,#59][s]: move packages/portal => examples/catalog as per plan in #59.

What is currently packages/portal is example of a running portal and should move to examples (it will get replaced by an actual portal lib soon).

examples/catalog/components/_shared/Error.tsx

@@ -0,0 +1,17 @@
+const ErrorMessage: React.FC<{ message: any }> = ({ message }) => {
+  return (
+    <aside>
+      {message}
+      <style jsx>{`
+        aside {
+          padding: 1.5em;
+          font-size: 14px;
+          color: white;
+          background-color: red;
+        }
+      `}</style>
+    </aside>
+  );
+};
+
+export default ErrorMessage;