Create an enum for Message status

src/Appwrite/Enum/MessageStatus.php

@@ -0,0 +1,27 @@
+<?php
+
+namespace Appwrite\Enum;
+
+enum MessageStatus: string
+{
+    /**
+     * Message that is not ready to be sent
+     */
+    case Draft = 'draft';
+    /**
+     * Scheduled to be sent for a later time
+     */
+    case Scheduled = 'scheduled';
+    /**
+     * Picked up by the worker and starting to send
+     */
+    case Processing = 'processing';
+    /**
+     * Sent without errors
+     */
+    case Sent = 'sent';
+    /**
+     * Sent with some errors
+     */
+    case Failed = 'failed';
+}