[BUGFIX] Replace usage of btn-block

Usage of button specific classes was mostly removed
in bootstrap 5. However, core still supports some of
those classes, e.g. "btn-block".

Using those classes however often leads to misbehavior
updating other components, which rely on newer layout
technologies.

To circumvent this, usage of the "btn-block" class is
migrated at all places, while the class definition is still
kept for backwards compatibility.

Resolves: #97891
Related: #97809
Related: #93119
Releases: main
Change-Id: I0308207e4e34d52512141658797046ac470514f1
Reviewed-on: https://review.typo3.org/c/Packages/TYPO3.CMS/+/75098


Tested-by: core-ci <typo3@b13.com>
Tested-by: Andreas Fernandez <a.fernandez@scripting-base.de>
Tested-by: Jochen <rothjochen@gmail.com>
Tested-by: Oliver Bartsch <bo@cedev.de>
Reviewed-by: Andreas Fernandez <a.fernandez@scripting-base.de>
Reviewed-by: Jochen <rothjochen@gmail.com>
Reviewed-by: Oliver Bartsch <bo@cedev.de>