Closing a streaming response body hangs if the server doesn't write

[sfackler]

What happened?

When closing the response body for a request to an endpoint that the server never finishes writing to, the close call hangs until the socket-level read timeout is reached inside of hasSubstantialRemainingData. Currently the only way to avoid the hang is to intentionally not close the response body, which can then trigger the leak detection warnings in Dialogue.

What did you want to happen?

Dialogue should be able to handle hung responses. Either the hasSubstantialRemainingData call should happen under a fairly aggressive timeout, or there should be some way to close the response without trying to consume any more of it.