[TASK] Allow AjaxDataHandler to pick button labels for Modal

Use AjaxDataHandler with Modal API without TYPO3.Language inline.
Allow Modal API to pick button labels when wrapped in AjaxDataHandler

Resolves: #65466
Releases: master
Change-Id: Ibe1385e41a8481620af74a3af6b3c4a49485fe4f
Reviewed-on: http://review.typo3.org/37467


Reviewed-by: Frank Nägler <typo3@naegler.net>
Tested-by: Frank Nägler <typo3@naegler.net>
Reviewed-by: Anja Leichsenring <aleichsenring@ab-softlab.de>
Tested-by: Anja Leichsenring <aleichsenring@ab-softlab.de>