Add wysiwyg plugin for file entities

Yep, this works for me. Annoying warnings for unrelated stuff now hidden leaving me in a blissful state of ignorance. Thanks. :-)

I addressed this by creating a couple of dummy process plugins to silence it.

namespace Drupal\example\Plugin\MediaWysiwyg;

use Drupal\media_migration\MediaWysiwygPluginBase;

/**
 * Field collection Media WYSIWYG plugin.
 *
 * This plugin targets field collection content entity types.
 *
 * @MediaWysiwyg(
 *   id = "field_collection_item",
 *   label = @Translation("Field Collection Item"),
 *   entity_type_map = {
 *     "field_collection_item" = "node",
 *   },
 * )
 *
 * @see \Drupal\media_migration\MediaWysiwygInterface
 */
class FieldCollectionItem extends MediaWysiwygPluginBase {}

namespace Drupal\example\Plugin\MediaWysiwyg;

use Drupal\media_migration\MediaWysiwygPluginBase;
/**
 * File Media WYSIWYG plugin.
 *
 * This plugin targets file content entity.
 *
 * @MediaWysiwyg(
 *   id = "file",
 *   label = @Translation("File"),
 *   entity_type_map = {
 *     "file" = "media",
 *   },
 * )
 *
 * @see \Drupal\media_migration\MediaWysiwygInterface
 */
class File extends MediaWysiwygPluginBase { }