HPCC-9645 Fix problems with adding newAtom to selects from child rows

Signed-off-by: Gavin Halliday <gavin.halliday@lexisnexis.com>
Merge pull request #4614 from ghalliday/issue9645

HPCC-9645 Fix problems with adding newAtom to selects from child rows

Reviewed-By: Richard Chapman <rchapman@hpccsystems.com>