Add CKEditor5PluginPack for better editorial experience

Problem/Motivation

There's some great things in CKEditor 5 Plugin Pack that our content editors will get really excited over.

* Text Transformation — specifically smart quotes
* Word Count
* Find & Replaces
* Full-screen mode

There's a few things in here that we should **avoid** adding by default:
* To-do Lists — not useful for most of our content and it would just be something extra to style/maintain
* Block Indentation??? — I'm not totally sure what this is. But the standard indentation seems to work just fine.
* Highlight — not useful for most of our content and it would just be something extra to style/maintain
* Fonts — our designers/front-end engineers would come for our skins if we added this
* WProofreader — Sounds like an upsell. I don't want to offer our clients something that they'll be advertised about in the CMS.
* Templates — Here be dragons. This is what paragraphs/layout-builder/etc. is for

Proposed resolution

* Add module with config described above

Remaining tasks