Add frontend component page for not found

Improve ErrorPage

js/src/forum/components/ErrorPage.js

@@ -0,0 +1,13 @@
+import Page from '../../common/components/Page';
+
+export default class NotAuthenticatedErrorPage extends Page {
+  view() {
+    return (
+      <div className="ErrorPage">
+        <div className="container">
+          <p>Error!</p>
+        </div>
+      </div>
+    );
+  }
+}

js/src/forum/routes.js

@@ -4,6 +4,7 @@ import PostsUserPage from './components/PostsUserPage';
 import DiscussionsUserPage from './components/DiscussionsUserPage';
 import SettingsPage from './components/SettingsPage';
 import NotificationsPage from './components/NotificationsPage';
+import ErrorPage from './components/ErrorPage';
 import DiscussionPageResolver from './resolvers/DiscussionPageResolver';
 
 /**
@@ -24,6 +25,8 @@ export default function (app) {
 
     settings: { path: '/settings', component: SettingsPage },
     notifications: { path: '/notifications', component: NotificationsPage },
+  
+    error: { path: '/:error', component: ErrorPage },
   };
 
   /**