[client, relay-server] Feature/relay notification (#4083)

- Clients now subscribe to peer status changes.
- The server manages and maintains these subscriptions.
- Replaced raw string peer IDs with a custom peer ID type for better type safety and clarity.

client/iface/wgproxy/factory_kernel.go

@@ -36,9 +36,8 @@ func (w *KernelFactory) GetProxy() Proxy {
 		return udpProxy.NewWGUDPProxy(w.wgPort)
 	}
 
-	return &ebpf.ProxyWrapper{
-		WgeBPFProxy: w.ebpfProxy,
-	}
+	return ebpf.NewProxyWrapper(w.ebpfProxy)
+
 }
 
 func (w *KernelFactory) Free() error {