The contents of footnotes, endnotes and comments were read with the
namespace prefixes declared in word/document.xml rather than in their
own parts. If word/footnotes.xml, word/endnotes.xml or word/comments.xml
declared a prefix that document.xml did not, such as `r` or `m`, the
elements using it were dropped: a hyperlink in a footnote lost its text,
and an equation in an endnote or comment disappeared. They are now read
with the namespace maps that archiveToNotes and archiveToComments
already compute.
Closes#11991.
Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>
