[TASK] EXT:dbal: Harden unit tests for expression chunks

The unit tests for the new expression chunking do not cover every
possible case. The tests are improved to avoid further regressions
in the new expression chunking. For a better understanding, the
expected WHERE conditions are written in the comments of some
non-obvious tests.

Resolves: #63373
Related: #63345, #61654
Releases: master, 6.2
Change-Id: I9e94fa315afc023e84854017230cd008e211059e
Reviewed-on: http://review.typo3.org/34703
Reviewed-by: Christian Kuhn <lolli@schwarzbu.ch>
Tested-by: Christian Kuhn <lolli@schwarzbu.ch>
Reviewed-by: Markus Klein <klein.t3@reelworx.at>
Tested-by: Markus Klein <klein.t3@reelworx.at>
Reviewed-by: Anja Leichsenring <aleichsenring@ab-softlab.de>
Tested-by: Anja Leichsenring <aleichsenring@ab-softlab.de>
Reviewed-by: Frans Saris <franssaris@gmail.com>
Tested-by: Frans Saris <franssaris@gmail.com>