Summary:
Add ZcrxIOThreadPoolExecutor, an IOThreadPoolExecutor subclass that creates an IOThreadPoolExecutor configured for io_uring zero-copy receive (zcrx). This class
allows any user to make use of the zcrx support and setup everything needed to use it.

Integrate it into the StressTestServer to support zcrx mode with automatic queue configuration and callback assignment.

Reviewed By: jlhe97

Differential Revision: D100186503

fbshipit-source-id: 4a7cbf2e5620b20a2062359a3e3b395009caa68f