LibCore+LookupServer: Implement and use UDPServer::send

Author: https://github.com/sin-ack
Commit: 0cca6cef95
Pull-request: https://github.com/SerenityOS/serenity/pull/9977
Reviewed-by: https://github.com/Dexesttp
Reviewed-by: https://github.com/alimpfard
Reviewed-by: https://github.com/awesomekling

Userland/Services/LookupServer/DNSServer.cpp

@@ -58,7 +58,9 @@ void DNSServer::handle_client()
         response.set_code(DNSPacket::Code::NOERROR);
 
     buffer = response.to_byte_buffer();
-    sendto(fd(), buffer.data(), buffer.size(), 0, (const sockaddr*)&client_address, sizeof(client_address));
+
+    // FIXME: We should be handling errors here.
+    [[maybe_unused]] auto result = send(buffer, client_address);
 }
 
 }