Conversion throws when an inline comment marker is in a list in a blockquote

The following makes fails to convert:

<blockquote>
  <ol>
    <li><ac:inline-comment-marker ac:ref="31c632a6-86ec-4a76-9cad-b39db413b79c">hello</ac:inline-comment-marker>
    </li>
  </ol>
</blockquote>

When onWord("hello") is produced, a beginFormat(NONE) is automatically inserted because of the ac:ref parameter of the ac:inline-comment-marker tag. No corresponding endFormat() is produced at the end of the list item and this seems to confuse the renderer. This doesn't happen when no blockquote surrounds the list, for some reason. While debugging, I seem to have seen that the beginFormat happens because closeFormat is called, but ultimately no closeFormat is produced. This doesn't affect the regular XWiki (X)HTML syntax because we have a complex list handling that bypasses wikimodel and the regular XHTML syntax doesn't, and possibly because the regular XHTML syntax doesn't have a handler for ac:inline-comment-marker.

Note that something similar happens when the ac:inline-comment-marker tag is replaced with a strong tag with no parameter but this time, the conversion doesn't fail.

inserting a corresponding endFormat when there's no matching one at the end of the list item seems to make things work.

Note: the xwiki syntax doesn't support lists in blockquotes (see https://forum.xwiki.org/t/handle-nested-block-quotes-in-xwiki-syntax-or-in-a-macro/16991), but that's a separate issue.