Refactor some frontend problems (#32646)

1. correct the modal usage on "admin email list" page (then
`web_src/js/features/admin/emails.ts` is removed)
2. use `addDelegatedEventListener` instead of `jQuery().on`
3. more jQuery related changes and remove jQuery from
`web_src/js/features/common-button.ts`
4. improve `confirmModal` to make it support header, and remove
incorrect double-escaping
5. fix more typescript related types
6. fine tune devtest pages and add more tests

web_src/js/features/repo-issue-list.ts

@@ -76,7 +76,7 @@ function initRepoIssueListCheckboxes() {
     // for delete
     if (action === 'delete') {
       const confirmText = e.target.getAttribute('data-action-delete-confirm');
-      if (!await confirmModal(confirmText, {confirmButtonColor: 'red'})) {
+      if (!await confirmModal({content: confirmText, confirmButtonColor: 'red'})) {
         return;
       }
     }