HPCC-10541 Add a COUNTER to JOIN

Signed-off-by: Gavin Halliday <gavin.halliday@lexisnexis.com>
Merge pull request #5941 from ghalliday/issue10541

HPCC-10541 Add a COUNTER to JOIN

Reviewed-By: Jamie Noss <james.noss@lexisnexis.com>
Reviewed-By: Jake Smith <jake.smith@lexisnexis.com>
Reviewed-By: Richard Chapman <rchapman@hpccsystems.com>