Add PreCheckoutQueryEvent handling

src/TgBotLib/Events/PreCheckoutQueryEvent.php

@@ -0,0 +1,29 @@
+<?php
+
+    namespace TgBotLib\Events;
+
+    use TgBotLib\Abstracts\UpdateEvent;
+    use TgBotLib\Bot;
+    use TgBotLib\Enums\UpdateEventType;
+    use TgBotLib\Objects\Payments\PreCheckoutQuery;
+
+    abstract class PreCheckoutQueryEvent extends UpdateEvent
+    {
+        /**
+         * @inheritDoc
+         */
+        public static function getEventType(): UpdateEventType
+        {
+            return UpdateEventType::PRE_CHECKOUT_QUERY;
+        }
+
+        /**
+         * New incoming pre-checkout query. Contains full information about checkout
+         *
+         * @return PreCheckoutQuery
+         */
+        protected function getPreCheckoutQuery(): PreCheckoutQuery
+        {
+            return $this->update->getPreCheckoutQuery();
+        }
+    }