adding some HTML to accordion title

I added a second MR where I upgrade the solution to work with the non-jquery version in 2.0.x branch for everyone using this and doing an upgrade.

It would also need to be possible to add language spans if one of the accordion titles is in a different language.

I added a second MR where I upgrade the solution to work with the non-jquery version in 2.0.x branch for everyone using this and doing an upgrade.

This change is actually necessary for the accordion to work at all in the 2.0.x version if the behaviors are attached more than once. I think maybe the once function isn't working properly?

Notice that once is not added as a parameter where it should be:

  dependencies:
    - core/drupal
    - core/drupalSettings
    - core/once

/**
 * @file
 * CKEditor Accordion functionality.
 */

(function (Drupal, drupalSettings) {
  'use strict';
...
})(Drupal, drupalSettings);

Marking as a bug report because of this.

Applying the changes in MR 12 fixes the issue.