[TASK] Enhance CKEditor5 whitespace plugin handling

This patch ensures that the whitespace plugin is correctly
removed, this includes the plugin itself and the toolbar item.
An additional plugin map of "softhyphen" to "Whitespace"
ensures that existing configurations are respected as well.
If the "softhyphen" Plugin was configured to be removed,
it will now remove the "Whitespace" plugin that is a
replacement.

Resolves: #99514
Releases: main
Change-Id: I18016141c187ef069be912c8d47017b2f4423b55
Reviewed-on: https://review.typo3.org/c/Packages/TYPO3.CMS/+/77326


Tested-by: Andreas Fernandez <a.fernandez@scripting-base.de>
Tested-by: core-ci <typo3@b13.com>
Reviewed-by: Benni Mack <benni@typo3.org>
Reviewed-by: Andreas Fernandez <a.fernandez@scripting-base.de>
Tested-by: Benni Mack <benni@typo3.org>