Support Unix socket transport on Windows platform

[arixmkii]

It currently returns error "protocol not supported"

go-connections/sockets/sockets_windows.go

Line 13 in 5df8d2b

return ErrProtocolNotAvailable

But modern Windows version support AF_UNIX https://devblogs.microsoft.com/commandline/af_unix-comes-to-windows/ and it can possibly be used as a transport for Docker or Docker compatible APIs if the container provider decides to expose this in addition to named pipes or if user decides to use some sort of ncat like tool to forward npipe to unix socket for the experience more close to that on other platforms.

[arixmkii]

Looks like it has already approved PR for this #115