Fix CKEditor 5 overflow & z-index problems inside Core Dialogs

We can fix the z-index problem, we can't fix the cropped flyout. The flyout problem should be handled by CKEditor itself. Also, the flyouts aren't 'cropped', it's possible to scroll the container to the right while it's open. This is not great, but determining the right direction for the flyout is a JS task.

Setting back to active, as this was merged into 3.x but never into the active 2.x - perhaps for good reasons or not. We need to clarify that as of 📌 What is the 3.x-dev for? Active

Can not cherry-pick this in 2.x for some reason...

ommit cherry-pick failed: Can't perform this action automatically. It may have already been done, or a more recent commit may have updated some of this content. Please perform this action locally.

So someone else needs to do it.

2.x doesn't matter anymore, 3.x becomes the new stable.

Automatically closed - issue fixed for 2 weeks with no activity.