[FEATURE] Add CKEditor Inspector for backend RTE forms

This feature adds the CKEditor Inspector to backend RTE forms in
Development context with $GLOBALS['TYPO3_CONF_VARS']['BE']['debug']
or the CKEditor configuration `editor.config.debug` being set.

The Inspector aids plugin developers in debugging the intermediate
CKEditor model.

Resolves: #100284
Releases: main
Change-Id: Ie18cd6c0b9854304fd3cbea521f5a434d4520a0e
Reviewed-on: https://review.typo3.org/c/Packages/TYPO3.CMS/+/78243


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