migrate groups:issues to static bundle

app/assets/javascripts/dispatcher.js

@@ -53,11 +53,6 @@ var Dispatcher;
         case 'projects:issues:show':
           shortcut_handler = true;
           break;
-        case 'groups:issues':
-          import('./pages/groups/issues')
-            .then(callDefault)
-            .catch(fail);
-          break;
         case 'groups:merge_requests':
           import('./pages/groups/merge_requests')
             .then(callDefault)

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

@@ -2,9 +2,9 @@ import projectSelect from '~/project_select';
 import initFilteredSearch from '~/pages/search/init_filtered_search';
 import { FILTERED_SEARCH } from '~/pages/constants';
 
-export default () => {
+document.addEventListener('DOMContentLoaded', () => {
   initFilteredSearch({
     page: FILTERED_SEARCH.ISSUES,
   });
   projectSelect();
-};
+});