Extend netbird status command to include health information (#1471)

* Adds management, signal, and relay (STUN/TURN) health probes to the status command.

* Adds a reason when the management or signal connections are disconnected.

* Adds last wireguard handshake and received/sent bytes per peer

signal/client/client.go

@@ -35,6 +35,7 @@ type Client interface {
 	GetStatus() Status
 	Receive(msgHandler func(msg *proto.Message) error) error
 	Ready() bool
+	IsHealthy() bool
 	WaitStreamConnected()
 	SendToStream(msg *proto.EncryptedMessage) error
 	Send(msg *proto.Message) error