Implement `SO_ERROR` for sockets

This `SO_ERROR` is commonly used to check sockets for errors, for example on non-blocking `connect` calls.

```c
getsockopt(sockfd, SOL_SOCKET, SO_ERROR, ...);
```

This is exposed in Rust as [`TcpStream::take_error`](https://doc.rust-lang.org/stable/std/net/struct.TcpStream.html#method.take_error), [`TcpListener::take_error`](https://doc.rust-lang.org/stable/std/net/struct.TcpListener.html#method.take_error), and [`UdpSocket::take_error`](https://doc.rust-lang.org/stable/std/net/struct.UdpSocket.html#method.take_error) via the currently not implemented [`std::sys::pal::hermit::net::Socket::take_error`](https://github.com/rust-lang/rust/blob/1.80.1/library/std/src/sys/pal/hermit/net.rs#L309-L311).