Keep CKEditor notifications on top of dialogs

Currently paste buttons in CKEditor don't work as expected due to a security restriction in browsers. When pressing the button, an alert is shown asking for using a shortcut (CTRL+V) instead.

Steps to reproduce it:

1. Copy an extract from a word document on the clipboard
2. In admin central create a basic page and add a text and image component within
3. When filling the component's dialog, press paste buttons

In Magnolia 6.0/6.2 you will see the message after pressing several times the button as it appears behind the dialog: (update: still the same also in M6.1.4 and M6.2.22)

In Magnolia 5.7 and earlier you will see the following:

Those buttons shouldn't appear anymore.

Additionally, this feature has been added again through a context menu in CKEditor 5 v11.2.0 (no paste buttons anymore). It might be interesting to update CKEditor to version 5 so that editors could make use of both the shortcut and the right-click menu to paste the content.

Notes
Here is an updated screenshot from 6.2.22. Click the button several times and watch the bottom of the screen:

Also if you go to the paste from word demo area for the ckeditor you get the same problem.

Workaround
Paste buttons won't appear by simply replacing a line in our configuration file: 5
From:

{ name: "clipboard",     items: [ "Cut", "Copy", "Paste", "PasteText", "PasteFromWord" ] },

To:

{ name: "clipboard",     items: [ "Cut", "Copy"] },