Add test coverage for babel_menu_link_content and functional test for export / import
>>> [!note] Migrated issue
<!-- Drupal.org comment -->
<!-- Migrated from issue #3535168. -->
Reported by: [huzooka](https://www.drupal.org/user/281301)
Related to !11
>>>
<h3 id="summary-problem-motivation">Problem/Motivation</h3>
<p>Follow-up (or the second part of) #3534188.</p>
<h3 id="summary-remaining-tasks">Remaining tasks</h3>
<ol>
<li>Test for menu link content translation type plugin</li>
<li>Test spreadsheet export/import (functional, js?)</li>
<li>Check which module service(s) can benefit from dedicated tests, and add test coverage for them</li>
</ol>
<h3 id="summary-ui-changes">User interface changes</h3>
<p>Nothing.</p>
<h3 id="summary-api-changes">API changes</h3>
<p>Nothing.</p>
<h3 id="summary-data-model-changes">Data model changes</h3>
<p>Nothing.</p>
issue