[TASK] Unsplit the splitbutton

[TASK] Unsplit the splitbutton

This patch splits the splitbutton into several separate buttons, which
all serve a single action. Modals are used for guiding the user
to prevent possible data loss based on their actions.

Concept: Rachel Foucard
Proofread: Tom Warwick
Resolves: #84753
Releases: master
Change-Id: I58bfe7621b1bc03ef9222bca740dbbe050c07fc9
Reviewed-on: https://review.typo3.org/56693
Tested-by: TYPO3com <no-reply@typo3.com>
Reviewed-by: Frank Naegler <frank.naegler@typo3.org>
Tested-by: Frank Naegler <frank.naegler@typo3.org>
Reviewed-by: Susanne Moog <susanne.moog@typo3.org>
Tested-by: Susanne Moog <susanne.moog@typo3.org>