Method co_dequeue

src/common/utils/BoundedQueue.h:43–49

  }

  folly::coro::Task<T> co_dequeue() {
    co_await dequeueSemaphore_.co_wait();
    T item;
    queue_.readIfNotEmpty(item);
    enqueueSemaphore_.signal();
    co_return item;
  }

  void dequeue(T &item) {
    dequeueSemaphore_.wait();