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

Resolves: #50907
Releases: 6.2, 6.1, 6.0
Change-Id: Iecb0a0b5db6c5caffad2210242a709e7310269ff
Reviewed-on: https://review.typo3.org/23876
Reviewed-by: Wouter Wolters
Tested-by: Wouter Wolters