add nftables config and deployment tasks for resolv-dns host

resources/resolv-dns/files/nftables.conf

@@ -0,0 +1,26 @@
+#!/usr/sbin/nft -f
+
+# only flush tables managed by this file
+table inet filter
+flush table inet filter
+
+table inet filter {
+	chain input {
+		type filter hook input priority filter; policy drop;
+		ip protocol icmp accept
+		ip6 nexthdr icmpv6 accept
+		iifname lo accept
+		ct state related,established accept
+
+		tcp dport 22 accept
+		tcp dport 53 accept
+		udp dport 53 accept
+	}
+	chain forward {
+		type filter hook forward priority filter; policy drop;
+		ct state related,established counter accept
+	}
+	chain output {
+		type filter hook output priority filter;
+	}
+}