Try using `AsynchronousSocketChannel`

Currently, our socket code uses blocking read calls on a separate thread.

This could be migrated to `AsynchronousSocketChannel` that's `Future`-based, and that would allow to make the code better, use fewer resources (no thread stack), and also maybe even fix the issues like #84.

Start by locating the socket code and its blocking reads on a separate thread. Compare that implementation with Java's AsynchronousSocketChannel and its Future-based API, then verify that the migration reduces thread-stack use and investigate whether it affects the issues described in #84.

Written by the indexing model from the issue text.