feat(core): Initial support for two-way communication over websockets (#7570)

- Enable two-way communication with web sockets
- Enable sending push messages to specific users
- Add collaboration service for managing active users for workflow

Missing things:
- State is currently kept only in memory, making this not work in
multi-master setups
- Removing a user from active users in situations where they go inactive
or we miss the "workflow closed" message
- I think a timer based solution for this would cover most edge cases.
I.e. have FE ping every X minutes, BE removes the user unless they have
received a ping in Y minutes, where Y > X
- FE changes to be added later by @MiloradFilipovic 

Github issue / Community forum post (link here to close automatically):

---------

Co-authored-by: कारतोफ्फेलस्क्रिप्ट™ <aditya@netroy.in>

packages/cli/test/unit/push/websocket.push.test.ts

@@ -0,0 +1,161 @@
+import Container from 'typedi';
+import { EventEmitter } from 'events';
+import type WebSocket from 'ws';
+import { WebSocketPush } from '@/push/websocket.push';
+import { Logger } from '@/Logger';
+import type { User } from '@/databases/entities/User';
+import type { PushDataExecutionRecovered } from '@/Interfaces';
+import { mockInstance } from '../../integration/shared/utils';
+
+jest.useFakeTimers();
+
+class MockWebSocket extends EventEmitter {
+	public isAlive = true;
+
+	public ping = jest.fn();
+
+	public send = jest.fn();
+
+	public terminate = jest.fn();
+
+	public close = jest.fn();
+}
+
+const createMockWebSocket = () => new MockWebSocket() as unknown as jest.Mocked<WebSocket>;
+
+describe('WebSocketPush', () => {
+	const sessionId1 = 'test-session1';
+	const sessionId2 = 'test-session2';
+	const userId: User['id'] = 'test-user';
+
+	mockInstance(Logger);
+	const webSocketPush = Container.get(WebSocketPush);
+	const mockWebSocket1 = createMockWebSocket();
+	const mockWebSocket2 = createMockWebSocket();
+
+	beforeEach(() => {
+		jest.resetAllMocks();
+	});
+
+	it('can add a connection', () => {
+		webSocketPush.add(sessionId1, userId, mockWebSocket1);
+
+		expect(mockWebSocket1.listenerCount('close')).toBe(1);
+		expect(mockWebSocket1.listenerCount('pong')).toBe(1);
+		expect(mockWebSocket1.listenerCount('message')).toBe(1);
+	});
+
+	it('closes a connection', () => {
+		webSocketPush.add(sessionId1, userId, mockWebSocket1);
+
+		mockWebSocket1.emit('close');
+
+		expect(mockWebSocket1.listenerCount('close')).toBe(0);
+		expect(mockWebSocket1.listenerCount('pong')).toBe(0);
+		expect(mockWebSocket1.listenerCount('message')).toBe(0);
+	});
+
+	it('sends data to one connection', () => {
+		webSocketPush.add(sessionId1, userId, mockWebSocket1);
+		webSocketPush.add(sessionId2, userId, mockWebSocket2);
+		const data: PushDataExecutionRecovered = {
+			type: 'executionRecovered',
+			data: {
+				executionId: 'test-execution-id',
+			},
+		};
+
+		webSocketPush.send('executionRecovered', data, sessionId1);
+
+		expect(mockWebSocket1.send).toHaveBeenCalledWith(
+			JSON.stringify({
+				type: 'executionRecovered',
+				data: {
+					type: 'executionRecovered',
+					data: {
+						executionId: 'test-execution-id',
+					},
+				},
+			}),
+		);
+		expect(mockWebSocket2.send).not.toHaveBeenCalled();
+	});
+
+	it('sends data to all connections', () => {
+		webSocketPush.add(sessionId1, userId, mockWebSocket1);
+		webSocketPush.add(sessionId2, userId, mockWebSocket2);
+		const data: PushDataExecutionRecovered = {
+			type: 'executionRecovered',
+			data: {
+				executionId: 'test-execution-id',
+			},
+		};
+
+		webSocketPush.broadcast('executionRecovered', data);
+
+		const expectedMsg = JSON.stringify({
+			type: 'executionRecovered',
+			data: {
+				type: 'executionRecovered',
+				data: {
+					executionId: 'test-execution-id',
+				},
+			},
+		});
+		expect(mockWebSocket1.send).toHaveBeenCalledWith(expectedMsg);
+		expect(mockWebSocket2.send).toHaveBeenCalledWith(expectedMsg);
+	});
+
+	it('sends data to all users connections', () => {
+		webSocketPush.add(sessionId1, userId, mockWebSocket1);
+		webSocketPush.add(sessionId2, userId, mockWebSocket2);
+		const data: PushDataExecutionRecovered = {
+			type: 'executionRecovered',
+			data: {
+				executionId: 'test-execution-id',
+			},
+		};
+
+		webSocketPush.sendToUsers('executionRecovered', data, [userId]);
+
+		const expectedMsg = JSON.stringify({
+			type: 'executionRecovered',
+			data: {
+				type: 'executionRecovered',
+				data: {
+					executionId: 'test-execution-id',
+				},
+			},
+		});
+		expect(mockWebSocket1.send).toHaveBeenCalledWith(expectedMsg);
+		expect(mockWebSocket2.send).toHaveBeenCalledWith(expectedMsg);
+	});
+
+	it('pings all connections', () => {
+		webSocketPush.add(sessionId1, userId, mockWebSocket1);
+		webSocketPush.add(sessionId2, userId, mockWebSocket2);
+
+		jest.runOnlyPendingTimers();
+
+		expect(mockWebSocket1.ping).toHaveBeenCalled();
+		expect(mockWebSocket2.ping).toHaveBeenCalled();
+	});
+
+	it('emits message event when connection receives data', () => {
+		const mockOnMessageReceived = jest.fn();
+		webSocketPush.on('message', mockOnMessageReceived);
+		webSocketPush.add(sessionId1, userId, mockWebSocket1);
+		webSocketPush.add(sessionId2, userId, mockWebSocket2);
+
+		const data = { test: 'data' };
+		const buffer = Buffer.from(JSON.stringify(data));
+
+		mockWebSocket1.emit('message', buffer);
+
+		expect(mockOnMessageReceived).toHaveBeenCalledWith({
+			msg: data,
+			sessionId: sessionId1,
+			userId,
+		});
+	});
+});