feat: add event dispatcher destructor and implement subscriber interface with tests (#23)

Reviewed-on: #23
Co-authored-by: Ron Rise <ron@siteworxpro.com>
Co-committed-by: Ron Rise <ron@siteworxpro.com>

src/Events/Subscribers/SubscriberInterface.php

@@ -0,0 +1,10 @@
+<?php
+
+declare(strict_types=1);
+
+namespace Siteworxpro\App\Events\Subscribers;
+
+interface SubscriberInterface
+{
+    public function handle(string $eventName, mixed $payload): mixed;
+}