HPCC-12443 Improve distributor tracing

Improve tracing to distinguish which distributor is tracing,
in activities with multiple distributors.

Signed-off-by: Jake Smith <jake.smith@lexisnexis.com>
Merge pull request #6555 from jakesmith/hpcc-12443

HPCC-12443 Improve distributor tracing

Reviewed-By: Richard Chapman <rchapman@hpccsystems.com>