HPCC-10288 - Add RemoveOwnedSubFiles

Signed-off-by: Jake Smith <jake.smith@lexisnexis.com>
Merge pull request #5061 from jakesmith/hpcc-10288b

HPCC-10288 - Add RemoveOwnedSubFiles

Reviewed-By: Gavin Halliday <gavin.halliday@lexisnexis.com>
Reviewed-By: Richard Chapman <rchapman@hpccsystems.com>