Remove customized (unmaintained) dropdown, improve aria a11y for dropdown (#19861)

* Remove customized (unmaintained) dropdown, improve aria a11y for dropdown

* fix repo permission

* use action instead of onChange

* re-order the CSS selector

* fix dropdown behavior for repo permissions, make elements inside menu item non-focusable

* use menu/menuitem instead of combobox/option. use tooltip(data-content) for aria-label, prevent from repeated attaching

* click menu item when pressing Enter

* code format

* fix repo permission

* repo setting: prevent from misleading users when error occurs

* fine tune the repo collaboration access mode dropdown (in case the access mode is undefined in the template)

Co-authored-by: zeripath <art27@cantab.net>
Co-authored-by: techknowlogick <techknowlogick@gitea.io>

web_src/js/features/common-global.js

@@ -4,6 +4,7 @@ import {mqBinarySearch} from '../utils.js';
 import createDropzone from './dropzone.js';
 import {initCompColorPicker} from './comp/ColorPicker.js';
 import {showGlobalErrorMessage} from '../bootstrap.js';
+import {attachDropdownAria} from './aria.js';
 
 const {appUrl, csrfToken} = window.config;
 
@@ -97,24 +98,27 @@ export function initGlobalCommon() {
   }
 
   // Semantic UI modules.
-  $('.dropdown:not(.custom)').dropdown({
+  const $uiDropdowns = $('.ui.dropdown');
+  $uiDropdowns.filter(':not(.custom)').dropdown({
     fullTextSearch: 'exact'
   });
-  $('.jump.dropdown').dropdown({
+  $uiDropdowns.filter('.jump').dropdown({
     action: 'hide',
     onShow() {
       $('.tooltip').popup('hide');
     },
     fullTextSearch: 'exact'
   });
-  $('.slide.up.dropdown').dropdown({
+  $uiDropdowns.filter('.slide.up').dropdown({
     transition: 'slide up',
     fullTextSearch: 'exact'
   });
-  $('.upward.dropdown').dropdown({
+  $uiDropdowns.filter('.upward').dropdown({
     direction: 'upward',
     fullTextSearch: 'exact'
   });
+  attachDropdownAria($uiDropdowns);
+
   $('.ui.checkbox').checkbox();
 
   // init popups