Use cases from #12352. The files correspond to
mwe-remove-bottom.23.lyx and mwe-remove-top.23.lyx. The only
differences are that I changed to FreeSans and FreeSerif for the
fonts.
Start a new directory of cprotect tests. There are many situations
where cprotect is needed so we can add files covering various
situations as we find them.
This particular test covers the case of special characters in URL
insets in footnotes.