[BUGFIX] Fix Typo3DbQueryParserTest for custom php timezones

The test setup used to initialize the DateAspect from a string,
that means the local php timezone has been taken into account,
and test verficiation fails with date offsets if the local
timezone is not UTC.

Adapt to initialize from a unix timestamp, as this ensures
the local timezone has no effect on the test. Note that the
real application does the same, as the DateAspect in initialized
from the timestamp in GLOBALS['EXEC_TIME'].

Releases: master, 10.4, 9.5
Resolves: #94135
Change-Id: I0494ac3e1911f34a3a79c3063caaabad1c0027b7
Reviewed-on: https://review.typo3.org/c/Packages/TYPO3.CMS/+/69141


Tested-by: core-ci <typo3@b13.com>
Tested-by: Tymoteusz Motylewski <t.motylewski@gmail.com>
Tested-by: Oliver Bartsch <bo@cedev.de>
Reviewed-by: Tymoteusz Motylewski <t.motylewski@gmail.com>
Reviewed-by: Oliver Bartsch <bo@cedev.de>