[BUGFIX] Form Wizard: Adds mouse pointer to docheader icons

Resolves: #50907
Releases: 6.2, 6.1, 6.0
Change-Id: I232498fea18b270e9436aeaf710f728a62365a4b
Reviewed-on: https://review.typo3.org/23875
Reviewed-by: Wouter Wolters
Tested-by: Wouter Wolters