Improve async/await usage, and sort init calls in index.js (#17386)

* clean up async/await, and sort init calls in `index.js
* use `const _promise` to indicate that we do not need await an async function

web_src/js/features/comp/SearchUserBox.js

@@ -2,7 +2,7 @@ import {htmlEscape} from 'escape-goat';
 
 const {appSubUrl} = window.config;
 
-export function initSearchUserBox() {
+export function initCompSearchUserBox() {
   const $searchUserBox = $('#search-user-box');
   $searchUserBox.search({
     minCharacters: 2,