Update CKEditor 5 to 46.0.0

Problem/Motivation

CKEditor v46 is out: https://github.com/ckeditor/ckeditor5/releases/tag/v46.0.0

It appears to have a large amount of breaking changes, so ideally we will get this in early in the Drupal 11.3 cycle to avoid the problems we had updating late to CKEditor v45 in Drupal 11.2.

Steps to reproduce

Proposed resolution

Update to CKEditor v46.
Fix things that are broken
Figure out what we need to tell contrib modules to do.

Remaining tasks

User interface changes

Introduced terminology

API changes

Data model changes

Release notes snippet