[TASK] Improve accessibility of "New form" multi-step wizard

This patch addds a basic keyboard navigation inside the multi-step wizard
for new forms in backend. This improves handling forms with the multiple
steps in this wizard.

Additionally, most useful input elements, such as input fields and next
step/finalize buttons are now focused by default when going to the next
slide. Also the focus styles were added to these elements.

Resolves: #90132
Releases: master
Change-Id: Ia668b727bf4cdba0e04ae409484dc44492360a33
Reviewed-on: https://review.typo3.org/c/Packages/TYPO3.CMS/+/63154


Tested-by: TYPO3com <noreply@typo3.com>
Tested-by: Oliver Bartsch <bo@cedev.de>
Tested-by: Andreas Fernandez <a.fernandez@scripting-base.de>
Reviewed-by: Oliver Bartsch <bo@cedev.de>
Reviewed-by: Andreas Fernandez <a.fernandez@scripting-base.de>