Incorrect handling of operational errors

[bzbarsky-apple]

See #28577 (review)

The immediate issue is the backwards check for "is our error different from the previous one?". But a bigger problem is a clear lack of tests for the functionality....

[bzbarsky-apple]

@cjandhyala

[hicklin]

The lack of test is due to the need of an application that can trigger an error state. We are in the process of building such a device application to allow us to test this and other events and states that are not testable at the moment.

[bzbarsky-apple]

The lack of test is due to the need of an application that can trigger an error state

@hicklin This could be done in all-clusters-app in a YAML test using either a new thing on the UnitTesting cluster or using TestEventTrigger... or maybe adding new YAML functionality to send messages down the pipe all-clusters-app is listening on for triggering its event.