Add support for listener shouldQueue method

[dmason30]

This PR adds support for the below functionality that exists on traditional listeners.

Conditionally Queueing Listeners

Sometimes, you may need to determine whether a listener should be queued based on some data that are only available at runtime. To accomplish this, a shouldQueue method may be added to a listener to determine whether the listener should be queued. If the shouldQueue method returns false, the listener will not be executed:

    <?php

    namespace App\Listeners;

    use App\Events\OrderCreated;
    use Illuminate\Contracts\Queue\ShouldQueue;

    class RewardGiftCard implements ShouldQueue
    {
        /**
         * Reward a gift card to the customer.
         */
        public function handle(OrderCreated $event): void
        {
            // ...
        }

        /**
         * Determine whether the listener should be queued.
         */
        public function shouldQueue(OrderCreated $event): bool
        {
            return $event->order->subtotal >= 5000;
        }
    }

Source: https://laravel.com/docs/10.x/events#conditionally-queueing-listeners

[lorisleiva]

Thanks for the contribution and for providing a test. 🍺