[ticket/16820] Move ATTACHMENT_CATEGORY_ constants to attachment namespace

PHPBB3-16820

phpBB/phpbb/attachment/attachment_category.php

@@ -0,0 +1,32 @@
+<?php
+/**
+ *
+ * This file is part of the phpBB Forum Software package.
+ *
+ * @copyright (c) phpBB Limited <https://www.phpbb.com>
+ * @license GNU General Public License, version 2 (GPL-2.0)
+ *
+ * For full copyright and license information, please see
+ * the docs/CREDITS.txt file.
+ *
+ */
+
+namespace phpbb\attachment;
+
+abstract class attachment_category
+{
+	/** @var int None category */
+	public const NONE = 0;
+
+	/** @var int Inline images */
+	public const IMAGE = 1;
+
+	/** @var int Not used within the database, only while displaying posts */
+	public const THUMB = 4;
+
+	/** @var int Browser-playable audio files */
+	public const AUDIO = 7;
+
+	/** @var int Browser-playable video files */
+	public const VIDEO = 8;
+}