[BUGFIX] Bring back select field button's functionality

Fix the missing CSS classes for the up/down/remove buttons of select
fields in FormEngine.

Resolves: #62591
Releases: master
Change-Id: I5ab3bda5a1170451a75e0c992cf2c6579bfb8c5d
Reviewed-on: http://review.typo3.org/33676
Reviewed-by: Frank Nägler <typo3@naegler.net>
Tested-by: Frank Nägler <typo3@naegler.net>
Reviewed-by: Markus Klein <klein.t3@reelworx.at>
Tested-by: Markus Klein <klein.t3@reelworx.at>