Client-side timeouts requests are not sent to X-Ray

Same as: https://github.com/aws/aws-xray-sdk-go/issues/289

When a request is too long to process by the server, and the client (or load balancer) closes the connexion because of a timeout, X-Ray does not send any info on Xray, which means we can't see what took so long during these requests...

Start by comparing this issue with aws-xray-sdk-go issue 289 and tracing how the Node.js SDK handles requests that end when the client or load balancer times out. Identify the relevant request and X-Ray reporting entry points; done means these client-side timeout requests produce usable X-Ray information about the slow request.

Written by the indexing model from the issue text.