HPCC-10633 ZAP report doesn't contain archive on legacy system

ZAP report doesn't contain the archive of the query if the query is
on a legacy eclserver based system. This fix retrieves the file contents
via the associated file list, and adds it to the ZIP file.

Signed-off-by: William Whitehead <william.whitehead@lexisnexis.com>
Merge pull request #5326 from RussWhitehead/ZapFix

HPCC-10633 ZAP report doesn't contain archive on legacy system

Reviewed-by: Gavin Halliday <ghalliday@hpccsystems.com>