HPCC-11203 Supply default cluster process on WsWorkunits.WUJobList

In this fix, a new item 'Process' is added to WUJobList request which
allows to specify a default thor process for retrieving WU jobs on
that process.

Signed-off-by: Kevin Wang kevin.wang@lexisnexis.com
Merge pull request #5691 from wangkx/h11203

HPCC-11203 Supply default cluster process on WsWorkunits.WUJobList

Reviewed-By: Gordon Smith <gordon.smith@lexisnexis.com>
Reviewed-By: Richard Chapman <rchapman@hpccsystems.com>