HPCC-9471 Change the parameter to queryAttribute to an enum

Signed-off-by: Gavin Halliday <gavin.halliday@lexisnexis.com>
Merge pull request #4500 from ghalliday/issue9471

HPCC-9471 Change the parameter to queryAttribute to an enum

Reviewed-By: Richard Chapman <rchapman@hpccsystems.com>