[GHS] Handle <script>

[Reinmar]

<script> is now ignored by GHS and cannot be enabled with it in any way.

[Reinmar]

Remarks:

• So far, we skipped <script> element when defining the data schema for GHS (

  ckeditor5/packages/ckeditor5-html-support/src/schemadefinitions.js

  Lines 48 to 49 in 89b5315

  	// noscript
  	// script

  ).
• Editing view:
  • The renderer will turn this element into a hidden span.
• Model:
  • <script> element can exist in block and inline contexts. This is - e.g directly in the root or inside <p>.
  • Model definition:
    • Allowed everywhere.
    • isInline: true, isBlock: false, isObject: false
  • Let's set the content of the script as an attribute of that model element.
• We need to support <script> element attributes too.
• We need to consider a training about GHS.

[Reinmar]

The behavior of this feature will be somehow similar to the behavior of the soft break.

[wimleers]

This will unblock https://www.drupal.org/project/drupal/issues/3245950 👍