Update Transformer Bank Rated kVA

This out-of-the-box autoupdater updates the rated kVA of a transformer by summing the rated kVAs of its transformer units. If the transformer’s Rated kVA field has a coded value domain, then that field is updated to show the domain value closest to the sum of the units’ kVA. If the transformer’s kVA field does not have a domain, then the value is set to the sum of the transformer units’ kVA. Any edits in the map that add or remove transformer units from the transformer bank fire this autoupdater.