[TASK] Improve unstable language tests

The notification js object gets "duration" as additional default value.
This can be increased for acceptance tests to ensure
notifications don't vanish before they are tested.
Activate two ac tests again that were disabled for that reason.

Resolves: #79963
Releases: master
Change-Id: Ib7bf046e7de1999fc693e08eeefc7d4c420bddae
Reviewed-on: https://review.typo3.org/51832


Tested-by: TYPO3com <no-reply@typo3.com>
Reviewed-by: Joerg Kummer <service@enobe.de>
Tested-by: Joerg Kummer <service@enobe.de>
Reviewed-by: Nicole Cordes <typo3@cordes.co>
Reviewed-by: Andreas Fernandez <typo3@scripting-base.de>
Reviewed-by: Christian Kuhn <lolli@schwarzbu.ch>
Tested-by: Christian Kuhn <lolli@schwarzbu.ch>