Add API for ServiceBusErrorSource in SB Track2

[hemanttanwar]

Introduce ServiceBusErrorSource, to help user identify source of the error. Specially in error handler in processor model.

For example

public enum ServiceBusErrorSource {
RECEIVE,
APPEND,
COMPLETE,
DEFER,
DEAD_LETTER,
}

[ramya-rao-a]

Originally, the error source came as a requirement to identify the source of the errors coming from background processes that tend to be applicable to

• receiving in the async client
• the processor model

Therefore, the only error sources we would need are

• complete (from when we try to auto complete)
• abandon (from when we try to abandon if user's callback failed)
• receive (from when we try to receive a message to pass to user's callback)
• renewLock (from when we try to renew lock for the received messages)
• user callback (from user's message callback)
• accepting a new session (when receiving from multiple sessions and we roll over to get a new session)

cc @hemanttanwar, @YijunXieMS, @conniey, @srnagar

[ramya-rao-a]

Done with #16710