[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

management/proto/management.proto

@@ -177,6 +177,8 @@ message WiretrusteeConfig {
 
   // a Signal server config
   HostConfig signal = 3;
+
+  RelayConfig relay = 4;
 }
 
 // HostConfig describes connection properties of some server (e.g. STUN, Signal, Management)
@@ -193,6 +195,13 @@ message HostConfig {
     DTLS = 4;
   }
 }
+
+message RelayConfig {
+  repeated string urls = 1;
+  string tokenPayload = 2;
+  string tokenSignature = 3;
+}
+
 // ProtectedHostConfig is similar to HostConfig but has additional user and password
 // Mostly used for TURN servers
 message ProtectedHostConfig {