HPCC-11592 ecl-queries-copy should copy the snapshot attribute

Signed-off-by: Anthony Fishbeck <anthony.fishbeck@lexisnexis.com>
Merge pull request #5995 from afishbeck/copyQuerySnapshot

HPCC-11592 ecl-queries-copy should copy the snapshot attribute

Reviewed-By: Richard Chapman <rchapman@hpccsystems.com>