As atto editor is deprecated there is the need to implement a feature to see orphaned files during usage of the new defaul editor tinymce.

The plugin atto orphand (see https://moodle.org/plugins/atto_orphaned )  https://tracker.moodle.org/browse/MDL-74277 should be ported to tinymce.

Plugin for Tiny: https://moodle.org/plugins/tiny_orphanedfiles