This patch adds support for loading the base CKEditor 5
locales and importing them in the backend if requested.

Because CKEditor doesn't ship a full set of locales, we
needed to add an additional build step that assembles
the locales of all plugins we have installed.

Resolves: #100873
Releases: main, 12.4
Change-Id: I971bf3e55d006a4a378123e8723c1bb8d23b09d1
Reviewed-on: https://review.typo3.org/c/Packages/TYPO3.CMS/+/79777


Tested-by: Andreas Nedbal <andy@pixelde.su>
Tested-by: core-ci <typo3@b13.com>
Reviewed-by: Andreas Nedbal <andy@pixelde.su>