Add site metadata to nomad and consul config so that nodes know where they are

configuration.nix

@@ -198,6 +198,9 @@ in
     else {}) //
   {
     datacenter = "staging";
+    node_meta = {
+      "site" = site_config.services.nomad.settings.datacenter;
+    };
     ui = true;
     bind_addr = public_ip;
 
@@ -240,6 +243,9 @@ in
     client = {
       enabled = true;
       network_interface = "wg0";
+      meta = {
+        "site" = site_config.services.nomad.settings.datacenter;
+      };
     };
     tls = {
       http = true;