cmd/cli: use powershell to set/reset DNS on Windows

Using netsh command will emit unexpected SOA queries, do not use it.

While at it, also ensure that local ipv6 will be added to nameservers
list on systems that require ipv6 local listener.

cmd/cli/cli.go

@@ -2661,6 +2661,7 @@ func resetDnsTask(p *prog, s service.Service) task {
 			iface = runningIface(s)
 		}
 		if isCtrldInstalled {
+			mainLog.Load().Debug().Msg("restore system DNS settings")
 			resetDnsNoLog(p)
 		}
 		iface = oldIface