Upgrade to CKEditor 5

[jebbdomingo]

Upgrade to the latest version of CKEditor to support webp image.
https://github.com/joomlatools/textman/issues/436

[johanjanssens]

@jebbdomingo If this requires a complete upgrade of CKEditor then that would be too much work. It's not need, people will not be uploading webp images, they are mostly converted on the fly from other image types.

[jebbdomingo]

@johanjanssens As with https://github.com/joomlatools/textman/issues/436, it works on TEXTman but there's still some bug in Joomla editor xtd buttons that needs further investigation. The major change that needs to be done in extensions that will use this is the new way to initialize/create an editor which now uses a promise. I created a small function to facilitate access to the created editors as v5 no longer uses a global repository of editors. I suggest we just leave this change for now for future reference.

[johanjanssens]

@jebbdomingo Oki, so you are suggestion to leave this as is and not upgrade it yet? Keep the PR open for future work?

[jebbdomingo]

@jebbdomingo Oki, so you are suggestion to leave this as is and not upgrade it yet? Keep the PR open for future work?

@johanjanssens Yes, sir.

[johanjanssens]

Agreed.