feat: use atlas in make pull_translations (#490)

Changes
-------
 - Bump frontend-platform to bring `intl-imports.js` script
 - Move all i18n imports into `src/i18n/index.js` so `intl-imports.js` can
   override it with latest translations
 - Add `atlas` into `make pull_translations` when `OPENEDX_ATLAS_PULL`
   environment variable is set.

Refs: [FC-0012 project](https://openedx.atlassian.net/l/cp/XGS0iCcQ) implementing Translation Infrastructure OEP-58.

src/i18n/index.js

@@ -1,3 +1,5 @@
+import { messages as footerMessages } from '@edx/frontend-component-footer';
+
 import arMessages from './messages/ar.json';
 import frMessages from './messages/fr.json';
 import es419Messages from './messages/es_419.json';
@@ -14,7 +16,7 @@ import ititMessages from './messages/it_IT.json';
 import ptptMessages from './messages/pt_PT.json';
 // no need to import en messages-- they are in the defaultMessage field
 
-const messages = {
+const appMessages = {
   ar: arMessages,
   'es-419': es419Messages,
   fr: frMessages,
@@ -31,4 +33,7 @@ const messages = {
   'pt-pt': ptptMessages,
 };
 
-export default messages;
+export default [
+  footerMessages,
+  appMessages,
+];

src/index.jsx

@@ -9,11 +9,9 @@ import React, { useEffect } from 'react';
 import ReactDOM from 'react-dom';
 import { Route, Switch } from 'react-router-dom';
 
-import { messages as footerMessages } from '@edx/frontend-component-footer';
-
 import { initializeHotjar } from '@edx/frontend-enterprise-hotjar';
 import { logError } from '@edx/frontend-platform/logging';
-import appMessages from './i18n';
+import messages from './i18n';
 
 import initializeStore from './store';
 import './index.scss';
@@ -79,9 +77,6 @@ initialize({
       }, 'CourseAuthoringConfig');
     },
   },
-  messages: [
-    appMessages,
-    footerMessages,
-  ],
+  messages,
   requireAuthenticatedUser: true,
 });