migrate groups:show to static bundle

app/assets/javascripts/dispatcher.js

@@ -356,9 +356,6 @@ var Dispatcher;
             .catch(fail);
           break;
         case 'groups:show':
-          import('./pages/groups/show')
-            .then(callDefault)
-            .catch(fail);
           shortcut_handler = true;
           break;
         case 'groups:group_members:index':

app/assets/javascripts/pages/groups/show/index.js

@@ -7,7 +7,7 @@ import ProjectsList from '~/projects_list';
 import ShortcutsNavigation from '~/shortcuts_navigation';
 import initGroupsList from '../../../groups';
 
-export default () => {
+document.addEventListener('DOMContentLoaded', () => {
   const newGroupChildWrapper = document.querySelector('.js-new-project-subgroup');
   new ShortcutsNavigation();
   new NotificationsForm();
@@ -19,4 +19,4 @@ export default () => {
   }
 
   initGroupsList();
-};
+});