[BUGFIX] Make debug exceptions scrollable in backend context

Resolves: #86132
Releases: master
Change-Id: I34a09ec83491b0f08e0a094680fbd93057ad76a4
Reviewed-on: https://review.typo3.org/58172


Reviewed-by: Andreas Fernandez <a.fernandez@scripting-base.de>
Tested-by: Andreas Fernandez <a.fernandez@scripting-base.de>
Tested-by: TYPO3com <no-reply@typo3.com>
Reviewed-by: Georg Ringer <georg.ringer@gmail.com>
Tested-by: Georg Ringer <georg.ringer@gmail.com>