[TASK] Change flashmessages.js for new FlashMessage styling

Extended previous patch to use correct class names for the message
containers.

Resolves: #62605
Releases: master
Change-Id: I4f99cd9f43dca26439f72553603f14ca190ccf05
Reviewed-on: http://review.typo3.org/34023


Reviewed-by: Frank Nägler <typo3@naegler.net>
Tested-by: Frank Nägler <typo3@naegler.net>
Reviewed-by: Wouter Wolters <typo3@wouterwolters.nl>
Tested-by: Wouter Wolters <typo3@wouterwolters.nl>
Reviewed-by: Stefan Froemken <froemken@gmail.com>
Tested-by: Stefan Froemken <froemken@gmail.com>
Reviewed-by: Christian Kuhn <lolli@schwarzbu.ch>
Tested-by: Christian Kuhn <lolli@schwarzbu.ch>