Allows send WebSocket message to any fd in current server, even the worker process does not hold the fd

[limingxinleo]

fix #403

<?php

declare(strict_types=1);

namespace App\Controller;

use Hyperf\HttpServer\Annotation\AutoController;
use Hyperf\WebSocketServer\Sender;

/**
 * @AutoController
 */
class HttpController extends Controller
{
    public function index()
    {
        $fd = $this->request->input('fd');

        $sender = $this-container->get(Sender::class);

        $sender->push((int) $fd, 'Hello Hyperf.');

        return $this->response->success();
    }
}

[limingxinleo]

@huangzhhui 都改过了

[huangzhhui]

这里应该改成获取 Swoole\Server

[smallsha123]

文档上咋没有

[huangzhhui]

文档上咋没有

这里并没有改变 WebSocket 本身的使用方式，我们只是加强了它的容错性，文档上也可以写一下我们会这么做