Network test : unit test for receiving from unbound unix socket.

Change-Id: If5c77feedf71161be00833711bda6ba41b0b4357
Reviewed-on: https://review.haiku-os.org/c/haiku/+/7549
Reviewed-by: Jérôme Duval <jerome.duval@gmail.com>
Haiku-Format: Haiku-format Bot <no-reply+haikuformatbot@haiku-os.org>
Tested-by: Commit checker robot <no-reply+buildbot@haiku-os.org>

unix: Implement datagram sockets

Implement `SOCK_DGRAM` sockets for `AF_UNIX` family.

Change-Id: If3d6f408a7d881635ccf04b080391905fdc94b13
Reviewed-on: https://review.haiku-os.org/c/haiku/+/6617
Reviewed-by: Jérôme Duval <jerome.duval@gmail.com>
Tested-by: Commit checker robot <no-reply+buildbot@haiku-os.org>