Initial LisgloSIPS V2 implementation

infra/server-a/s20/nftables/lisglosips-s20-observability.nft

@@ -0,0 +1,9 @@
+table inet lisglosips_s20_observability {
+  chain input {
+    type filter hook input priority -13; policy accept;
+    iif "lo" accept
+    ct state established,related accept
+    udp dport 9061 drop
+    tcp dport 6380 drop
+  }
+}