Allow binding ICMP sockets to a port for receiving Destination Unreachable messages
m-labs/smoltcp#69 allows users to bind
a icmp socket to a UDP port similar to the second section found at https://www.planet-lab.org/raw_sockets/api_icmp.html. Add icmp:upd/<port>
to the icmp scheme an allow users to receive ICMP error responses associated with an open UDP port.