fix: fix memory leak if timeout is set

[masontikhonov]

Note

Corresponding PR to upstream: apocas#178

Issue

Currently, if timeout option is provided, one more event listener is added to the underlying socket on each request. This causes the number of timeout event listeners for each socket to grow over time until the socket is destroyed. In my tests, the number of event listeners for single socket can exceed 400.

Moreover, it closures Request object within timeout handler preventing it from being garbage collected far beyond its lifecycle.

Resolution

This PR changes timeout implementation, by adding timeout event listener directly to the Request object instead of the Socket. Considering that request.setTimeout implicitly calls an appropriate socket.setTimeout() (docs); and timeout event is propagated from the underlying socket to the request itself (docs); the original behavior will remain unchanged.

At the same time this will prevent Socket event listeners count from growing and will also allow garbage collecting Request objects.

Also, this PR replaces deprecated request.abort() with request.destroy().