[BUGFIX] Prevent double encoding in button rendering

Multiple button settings are double encoded with htmlspecialchars. This
patch removes the hsc within the setters as the button settings are
already escaped during render method.

Resolves: #71915
Releases: master
Change-Id: I470b6e4ce42859d4147e21acf9e7b6334a776848
Reviewed-on: https://review.typo3.org/45014


Reviewed-by: Georg Ringer <georg.ringer@gmail.com>
Tested-by: Georg Ringer <georg.ringer@gmail.com>
Reviewed-by: Michael Oehlhof <typo3@oehlhof.de>
Tested-by: Michael Oehlhof <typo3@oehlhof.de>
Reviewed-by: Markus Klein <markus.klein@typo3.org>
Tested-by: Markus Klein <markus.klein@typo3.org>