Support tabbed interface [CKE5]

I created a patch for the ckeditor_details module (related ticket) that fixes the issue of having all details contents wrapped in a div.

I've got the new tabs plugin working within wxt_ext_editor. Tested this against complex migrated data as well as creating new tabs manually, works well! Will have a patch for WxT tomorrow, just need to adjust the text format configs to include this new plugin, and add the patch for ckeditor_details module.

Patch attached adds the new Tabbed interface CKEditor5 plugin. Here is a list of changes:

• Add new Tab plugin for CKEditor5
• Add patch to ckeditor_details to allow any child element for <details> element
• Add new Tab plugin to Rich Text (CKEditor5) text format
• Add new icon for Tab plugin - thanks to @crow (Craig Clark) for the new SVG icon

New Tab icon:

Just tested a fresh install and it works as expected. For existing sites, you just need to add the new icon to your text format, along with the details plugin, and it should just work.

This ticket would be good to get into the next release. Even just the patch I create for ckeditor_details is worth merging for, as it makes this plugin MUCH more robust. Without this, migrated content with details elements become unusable in CKE5, and this is a common component. The tabbed interface, although not as common, is also nice to have support for, else tabs are not editable in CKE5. This feature has been tested thoroughly with new content and migrated content.

This will be included in 6.1.x

This has been merged with 6.1.x.

Automatically closed - issue fixed for 2 weeks with no activity.