feat: refactor tests

Author: vladislavkeblysh

src/learning-header/AuthenticatedUserDropdown.test.jsx

@@ -1,6 +1,6 @@
 import React from 'react';
 import { render, screen, fireEvent } from '@testing-library/react';
-import { IntlProvider, defineMessages } from 'react-intl';
+import { IntlProvider, defineMessages } from '@edx/frontend-platform/i18n';
 import { getConfig } from '@edx/frontend-platform';
 import AuthenticatedUserDropdown from './AuthenticatedUserDropdown';