EventStream add return value

[tw2066]

通过增加write返回值;
1:可以判断客户端是否离线(返回false)
2:离线后可以做后续判断

        /** @var Response $response */
        $response = ApplicationContext::getContainer()->get(ResponseInterface::class);
        $result = [
            'data: 1' . PHP_EOL . PHP_EOL,
            'data: 2' . PHP_EOL . PHP_EOL,
            'data: 3' . PHP_EOL . PHP_EOL,
            'data: 4' . PHP_EOL . PHP_EOL,
            'data: 5' . PHP_EOL . PHP_EOL,
            'data: 6' . PHP_EOL . PHP_EOL,
        ];
        $eventStream = new EventStream($response->getConnection());
        foreach ($result as $stream) {
            $bool = $eventStream->write((string) $stream);
            dump($bool,$stream);
            if (! $bool) {
                return;
            }
            sleep(3);
        }
        $eventStream->end();