[BUGFIX] Fix styling in form wizard

Fix some styling issues of the ExtJS wizard in EXT:form

Resolves: #63473
Releases: master
Change-Id: I1f56c8c72883b6fd390f4d1d69290c3784d58539
Reviewed-on: http://review.typo3.org/34841
Reviewed-by: Jigal van Hemert <jigal.van.hemert@typo3.org>
Tested-by: Jigal van Hemert <jigal.van.hemert@typo3.org>
Reviewed-by: Andreas Fernandez <a.fernandez@scripting-base.de>
Tested-by: Andreas Fernandez <a.fernandez@scripting-base.de>
Reviewed-by: Helmut Hummel <helmut.hummel@typo3.org>
Tested-by: Helmut Hummel <helmut.hummel@typo3.org>