Add server deletion to a queue.

This action allows servers to be deleted, but only be soft-deleted for
10 minutes. After that time period the server will be completely
removed from the database and daemon. This allows some safety if a
server is accidentally deleted.

Force deleting a server will still work. If the daemon is in-accessible
the server will fail to be deleted. When server is soft-deleted admins
can still view its information page in the admin CP, however the server
will be suspended and inaccessible on the front-end or though the
daemon.

Admins can manually delete the server ahead of the delete timer, or if
it failed to delete previously they can do an immediate retry.

app/Providers/EventServiceProvider.php

@@ -13,8 +13,8 @@ class EventServiceProvider extends ServiceProvider
      * @var array
      */
     protected $listen = [
-        'Pterodactyl\Events\SomeEvent' => [
-            'Pterodactyl\Listeners\EventListener',
+        'Pterodactyl\Events\ServerDeleted' => [
+            'Pterodactyl\Listeners\DeleteServerListener',
         ],
     ];