Fix wf monitor to properly parse pims split stage names

Charlotte Hausmanrequested to merge
tweak-for-pims-logs into release/2.8.7.1

turns out this wasn't handling the '+' in pims split stage updates like below:

008 (041.000.000) 2025-03-28 17:01:24 WS STAGE UPDATE: Stage SPLIT_SQDEG/J130818+654200 has Completed at 2025-03-28 11:01:24.473543.
...

Merge request reports