Links to selected texts are generated without a corresponding anchor in the document content

Annotations are displayed in the comment section with a link on the selection text. These links appear to be broken: they have an anchor, but the corresponding anchor doesn't exist in the rendered document content.

Here is a case to reproduce the issue. The page was imported using the confluence-xml input filter stream, importing this package: https://github.com/xwiki-contrib/confluence/tree/master/confluence-xml/src/test/resources/confluencexml/annotations

Note: the state of the comments isn't set. Setting it to SAFE doesn't appear to change anything.

In any case, we shouldn't be generating links with a non-existent anchor.