Clean up event subscriptions for agent session when transfer.succeede…

[haomingli2020]

…d is received over websocket

Issue #, if available:

• Agent can use Quick Connect to transfer chat to another Agent.
• After transfer, current Agent chat connection - should not receive new messages from websocket
• this change, cleans up the event listeners and breaks the current chat connection after chat has successfully transferred.

Note: participantId is not provided and transfer.succeeded event is only fanned out to current Agent who initiated the transfer. If 1 or more Agents receive transfer.succeeded event, its expected that all of there chat connections should end.

{"AbsoluteTime":"2024-10-30T21:24:44.572Z","ContentType":"application/vnd.amazonaws.connect.event.transfer.succeeded","Id":"8ab8...","Type":"EVENT","InitialContactId":"bf6ae4fa-7eb7..."}

Before fix

After fix

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