[BUGFIX] Paste all items from clipboard into group field

If the clipboard contains at least one item, a paste button is rendered
next to fields of type `group`. With this patch, all items of the
clipboard are now pasted into the field.

Resolves: #88711
Releases: master, 9.5
Change-Id: Ib8d5d9ab148e8794f54d2665d95721c10f8b7255
Reviewed-on: https://review.typo3.org/c/Packages/TYPO3.CMS/+/63834


Tested-by: Susanne Moog <look@susi.dev>
Tested-by: TYPO3com <noreply@typo3.com>
Tested-by: Daniel Haupt <mail@danielhaupt.de>
Tested-by: Andreas Fernandez <a.fernandez@scripting-base.de>
Reviewed-by: Susanne Moog <look@susi.dev>
Reviewed-by: Daniel Haupt <mail@danielhaupt.de>
Reviewed-by: Andreas Fernandez <a.fernandez@scripting-base.de>