Receive a message/event rather than raising RuntimeError when agent iteration reaches maximum

[ekzhu]

Whether it's possible to get an event instead of RuntimeError when iteration exceeds maximum. I'm catching the runtime error and using string match to tell whether the workflow terminated because it reachse MAX_STEPS. Kind of ugly.

@ultmaster

[markwallace-microsoft]

@rogerbarreto would this make sense for MEAI also?