[BUGFIX] Fix CSS layout of cropper UI for Firefox

The fix is to remove previously introduced CSS hacks
and provide a cleaner and leaner base

Resolves: #79998
Resolves: #79989
Releases: master
Change-Id: Ic63b3acaf46f50f92a3c44578c28748dfca74351
Reviewed-on: https://review.typo3.org/51842


Tested-by: Jasmina Ließmann <code@frauliessmann.de>
Tested-by: TYPO3com <no-reply@typo3.com>
Reviewed-by: Jasmina Ließmann <code@frauliessmann.de>
Reviewed-by: Anders Kostending <aha@systime.dk>
Reviewed-by: Helmut Hummel <typo3@helhum.io>
Tested-by: Helmut Hummel <typo3@helhum.io>