Add MsgTemplate api to v4

Civi/Api4/MsgTemplate.php

@@ -0,0 +1,30 @@
+<?php
+
+/*
+ +--------------------------------------------------------------------+
+ | Copyright CiviCRM LLC. All rights reserved.                        |
+ |                                                                    |
+ | This work is published under the GNU AGPLv3 license with some      |
+ | permitted exceptions and without any warranty. For full license    |
+ | and copyright information, see https://civicrm.org/licensing       |
+ +--------------------------------------------------------------------+
+ */
+
+/**
+ *
+ * @package CRM
+ * @copyright CiviCRM LLC https://civicrm.org/licensing
+ */
+
+namespace Civi\Api4;
+
+/**
+ * MsgTemplate entity.
+ *
+ * This is a collection of MsgTemplate, for reuse in import, export, etc.
+ *
+ * @package Civi\Api4
+ */
+class MessageTemplate extends Generic\DAOEntity {
+
+}