To improve the usability, add tool tips to the icons.

Resolves: #75616
Releases: master, 7.6
Change-Id: Iceffc8d15625aa02da55ce533463951546d8d890
Reviewed-on: https://review.typo3.org/47666


Reviewed-by: Christian Kuhn <lolli@schwarzbu.ch>
Tested-by: Christian Kuhn <lolli@schwarzbu.ch>
Reviewed-by: Daniel Goerz <ervaude@gmail.com>
Tested-by: Daniel Goerz <ervaude@gmail.com>
Reviewed-by: Wouter Wolters <typo3@wouterwolters.nl>
Tested-by: Wouter Wolters <typo3@wouterwolters.nl>