HPCC-11775 Improve efficiency of WUiterate in Sasha

WUiterate which scans and filters archives and online workunits,
accessed Dali in an inefficient way, especially in the case of
requesting a single workunit.

Signed-off-by: Jake Smith <jake.smith@lexisnexis.com>
I don't think that is possible though.. the before and after are not-partial, so if really the same, would be e.g. W20140101-020304