lightning-charge: add netns

- Adds lightning-charge to netns-isolation.services
- Adds cfg.enforceTor to bring lightning-charge in line with other
  services
- Adds extraArgs option to allow using lightning-charge with network
  namespaces
- Adds host option (defaults to localhost) as target of hidden service

modules/presets/secure-node.nix

@@ -127,6 +127,8 @@ in {
       enforceTor = true;
     };
 
+    services.lightning-charge.enforceTor = true;
+
     services.nix-bitcoin-webindex.enforceTor = true;