[TASK] Add allowed file types to “images” field

The field is clearly designated for image formats, so we should by default allow all image types (and only those file types).

Author: davidsteeb

Configuration/TCA/tx_listelements_item.php

@@ -163,6 +163,7 @@
                 'appearance' => [
                     'createNewRelationLinkTitle' => 'LLL:EXT:listelements/Resources/Private/Language/locallang_db.xlf:tx_listelements_item.images.addFileReference',
                 ],
+                'allowed' => 'common-image-types'
             ],
         ],
         'assets' => [