Code Review for Job #19783

Code Review for Job #19783 - Workitem available at https://www.worklist.net/19783
I did test briefly, but I was hoping for some feedback about potential issues.  I would expect, at worst, that it would cause extra data to be sent in ModelEdit messages.  That said, it seems that this function is expecting an unchanged non-local ModelItem, and if that's true, this change doesn't make sense.

I think the best solution is to just create a new method that treats the ModelItem as local/new/unsynced - what would be the right term for this? Something like `copyFromLocalModelItem`?