Support for CKEditor 5

I've created plugin for CKEditor 5. It uses structure/tag of the current plugin, so it should be backwards compatible with already created content.

I had to update code and `cookie-content-blocker` library dependency to use `core/js-cookie`, since `jquery.cookie` was removed in D10.

thierry.beeckmans → made their first commit to this issue’s fork.

I reverted some unrelated changes.

The cookies variable name fix goes to 🐛 cookies is not defined Fixed

The jquery.once replacement goes to 🐛 Replace jquery/once by core/once Fixed

I fixed reported issues in code and UI.

sebastian.wegerer → made their first commit to this issue’s fork.

Thank you for the contribution. I will merge and release these changes.