feat(core): Add support for WebSockets as an alternative to Server-Sent Events (#5443)

Co-authored-by: Matthijs Knigge <matthijs@volcano.nl>

packages/cli/src/push/websocket.push.ts

@@ -0,0 +1,19 @@
+import type WebSocket from 'ws';
+import { AbstractPush } from './abstract.push';
+
+export class WebSocketPush extends AbstractPush<WebSocket> {
+	add(sessionId: string, connection: WebSocket) {
+		super.add(sessionId, connection);
+
+		// Makes sure to remove the session if the connection is closed
+		connection.once('close', () => this.remove(sessionId));
+	}
+
+	protected close(connection: WebSocket): void {
+		connection.close();
+	}
+
+	protected sendToOne(connection: WebSocket, data: string): void {
+		connection.send(data);
+	}
+}