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 know I suggested it, but this change is probably wrong
- the date range code may have created a mask when there wasn't one before (line 138).

I think the original line was fine - there isn't a need to check for !isWild