Support datagram endpoints over netlink sockets

Hi there,

please see: https://github.com/svinota/pyroute2/issues/1335

My project uses uvloop, however I've had to move back to asyncio as I have a dependency on pyroute2, and it doesn't work with uvloop.

This seems to be because uvloop doesn't support datagram endpoints over netlink sockets, whereas asyncio does.

Is this something that could be implemented?

Thanks,

David.