[relay] Feature/relay integration (#2244)

This update adds new relay integration for NetBird clients. The new relay is based on web sockets and listens on a single port.

- Adds new relay implementation with websocket with single port relaying mechanism
- refactor peer connection logic, allowing upgrade and downgrade from/to P2P connection
- peer connections are faster since it connects first to relay and then upgrades to P2P
- maintains compatibility with old clients by not using the new relay
- updates infrastructure scripts with new relay service

infrastructure_files/management.json.tmpl

@@ -20,6 +20,11 @@
         "Secret": "secret",
         "TimeBasedCredentials": false
     },
+    "Relay": {
+        "Addresses": ["rel://$NETBIRD_RELAY_DOMAIN:$NETBIRD_RELAY_PORT"],
+        "CredentialsTTL": "24h",
+        "Secret": "$NETBIRD_RELAY_AUTH_SECRET"
+    },
     "Signal": {
         "Proto": "$NETBIRD_SIGNAL_PROTOCOL",
         "URI": "$NETBIRD_DOMAIN:$NETBIRD_SIGNAL_PORT",