itExpects: More concise output when unexpected error logs cause a test to fail

[markfields]

Description

I got confused by the output of itExpects when unexpected errors were logged, because the output was too big but I didn't notice the ... at the end, so even after adding the errors it printed the first time, there were still more!

This change makes each error event more concise in the output, but will be good enough to get you oriented (and it's easy to tweak the primaryEventProps function if you want to check other properties).