McpClientFactory.CreateAsync incorrectly claims "Initialization timed out"

[AArnott]

Describe the bug

When the CancellationToken passed to McpClientFactory.CreateAsync in canceled before the method completes, it throws an ModelContextProtocol.McpException with the message "Initialization timed out".

This doesn't conform to .NET conventions.

To Reproduce

IMcpClient client = await McpClientFactory.CreateAsync(
   configuration.CreateClientTransport(id),
   clientOptions,
   cancellationToken: new CancellationToken(true));

Expected behavior

I expect an OperationCanceledException that merely expresses the operation is canceled -- not that something timed out (as there was in fact no timer).

[stephentoub]

This should be fixed by #321, but I've added a test to it to help confirm.