Failed to extract zip64 due to mising values in `is_zip64_`

[nyuware]

Describe the bug
We found in our corpus some zip files that fail to extract with out current zip handler.

After some investigation, the file seems to be a zip64 with FFFF values in the Central directory header.
sanity check: returning True in is_zip64_eocd correctly carves the zip file.

In conclusion, we should add coverage for zip files that have zip64 "informations" in their central directory headers