HandleMainLoopException puts exception StackTrace in the EventSource Message

[eerhardt]

Describe the bug

When a connection exception happens, we log a message to the RabbitMqClientEventSource. However, the full exception ToString is being logged in the Message of the EventSource event.

Reproduction steps

1. Add an EventListener to the rabbitmq-client EventSource.
2. Create a RabbitMQ connection to a server.
3. Stop the server to generate an exception
4. Observe the EventSource Error event data

This can easily be done with a .NET Aspire app that uses the RabbitMQ component and looking in the Structured Logs entry for the exception.

Expected behavior

The Message should only contain the message information. Not the StackTrace.

Additional context

I believe the issue is isolated to the HandleMainLoopException method. The other places that log exceptions all appear to pass the caught exception into the logging correctly.

In HandleMainLoopException, it puts the ShutdownEventArgs ToString() into the message.

rabbitmq-dotnet-client/projects/RabbitMQ.Client/client/impl/Connection.Receive.cs

Lines 176 to 187 in 1d5b36a

	private void HandleMainLoopException(ShutdownEventArgs reason)
	{
	if (!SetCloseReason(reason))
	{
	LogCloseError($"Unexpected Main Loop Exception while closing: {reason}", reason.Exception);
	return;
	}
	_channel0.MaybeSetConnectionStartException(reason.Exception);
	OnShutdown(reason);
	LogCloseError($"Unexpected connection closure: {reason}", reason.Exception);

And the ShutdownEventArgs ToString() puts the full exception.ToString() in the result:

rabbitmq-dotnet-client/projects/RabbitMQ.Client/client/api/ShutdownEventArgs.cs

Lines 129 to 137 in dd10278

	public override string ToString()
	{
	return $"AMQP close-reason, initiated by {Initiator}"
	+ $", code={ReplyCode}"
	+ (ReplyText != null ? $", text='{ReplyText}'" : string.Empty)
	+ $", classId={ClassId}"
	+ $", methodId={MethodId}"
	+ (Cause != null ? $", cause={Cause}" : string.Empty)
	+ (_exception != null ? $", exception={_exception}" : string.Empty);

We could fix this by adding a new method like "GetEventLogMessage()" method that contains all this information, but doesn't include the full ToString of the exception in the message.

See dotnet/aspire#2118 (comment) for more details.

[lukebakken]

Feel free to open a PR targeting 6.x. I can merge / port it into main.