When using the drupalmedia plugin to insert a media in the editor, the <drupal-media> element is wrapped in a div.cke_widget_wrapper on which no attributes are copied. When using the view mode or the alignment selectors, data attributes are added to the <drupal-media> element but not on its wrapper so it's not possible to add styles to preview how the media will be rendered in front.
The media should be aligned but it's not because its wrapper is a div taking the whole width.
Copy attributes to the wrapper so it can be styled according to the choices made in the editor.
Needs review
1.0
Code
Added one commit to handle the deletion of some attributes (ie. when removing the alignment).
Tests cannot pass because Classy has been removed from Drupal 10.1.
The failure is unrelated to this issue.