#3484395 CKE for component instances

Unlike most XB field widgets, which use Drupal default behaviors, this is approached different to take advantage of the CK team offering a dedicated CKEditor5 React component

Note that many lines of code added are copied from core's ckeditor5.js, and can be significantly reduced when [#3521761] lands as that will un-encapsulate them.

Getting CKEditor5 integrated gracefully - whether or not the CK React Component was used - also required removing several components that were added Fall 2024 for Drupalcon demo purposes. These looked great and had good UX, but were not "official" designs and were meant to be temporary. They also made it difficult for the editor and corresponding controls to actually work without significant spaghetti. If it turns out anything that they offered are missed, I'm sure they can return in some way, but will need to be implemented differently.

There are also many changes made to get tests passing, despite them likely being unrelated to any CKEditor5 changes. These instances have comments in the MR indicating them as such and while it's not fully clear if they are in scope, most of us are aware of how rickety the e2e situation is right now and I hope are OK with seemingly unrelated changes that improve that situation.