Allow other CKEditor 5 plugins to rerender drupal-media when their attribute changes

I quick tried this locally:

Modify DrupalMediaEditing to add

    this.converterAttributes = [
      'drupalMediaEntityUuid',
      'drupalElementStyleViewMode',
      'drupalMediaEntityType',
      'drupalMediaAlt',
    ];

My plugin in its init then has to do:

    const mediaEditing = editor.plugins.get('DrupalMediaEditing');
    mediaEditing.converterAttributes.push('drupalElementStyleMediaEmbedCode')
    console.log(mediaEditing.converterAttributes)
    mediaEditing._defineConverters();

It has to re-apply the converter listeners for the new attribute since everything is running in `init`. That's one reason why exporting `converter` would be better. My plugin has DrupalMediaEditing as a dependency, so init is messy.

The weird part is that everything breaks when I use:

        this.converterAttributes.forEach((attribute) => {
          dispatcher.on(attribute, converter);
        });

The media element never renders, only when I keep

        dispatcher.on(
          'attribute:drupalElementStyleMediaEmbedCode:drupalMedia',
          converter,
        );
        dispatcher.on('attribute:drupalMediaEntityUuid:drupalMedia', converter);
        dispatcher.on(
          'attribute:drupalElementStyleViewMode:drupalMedia',
          converter,
        );
        dispatcher.on('attribute:drupalMediaEntityType:drupalMedia', converter);
        dispatcher.on('attribute:drupalMediaAlt:drupalMedia', converter);

It didn't work because I failed to build the proper event name 😅. Opening an MR based on the following:

  constructor(editor) {
    super(editor);

    this.attrs = {
      drupalMediaAlt: 'alt',
      drupalMediaEntityType: 'data-entity-type',
      drupalMediaEntityUuid: 'data-entity-uuid',
    };
    this.converterAttributes = [
      'drupalMediaEntityUuid',
      'drupalElementStyleViewMode',
      'drupalMediaEntityType',
      'drupalMediaAlt',
    ];
  }

and

        this.converterAttributes.forEach((attribute) => {
          dispatcher.on(`attribute:${attribute}:drupalMedia`, converter);
        });

This allowed our plugin, in its constructor, to add another attribute:

  constructor(editor) {
    super(editor);

    const mediaEditing = editor.plugins.get('DrupalMediaEditing');
    mediaEditing.converterAttributes.push('drupalElementStyleMediaEmbedCode')
  }

Patches for 9.5.x and 9.4.x, if needed.