[TASK] Fix DB error message in Testbase

The error message now suggest a GRANT statement which supports
db name suffixes for both functional and acceptance tests.

Resolves: #74012
Releases: master
Change-Id: I121bb419f86e83f26154422bdcd378e586c54867
Reviewed-on: https://review.typo3.org/47010


Reviewed-by: Christian Kuhn <lolli@schwarzbu.ch>
Tested-by: Christian Kuhn <lolli@schwarzbu.ch>
Reviewed-by: Jan Helke <typo3@helke.de>
Tested-by: Jan Helke <typo3@helke.de>