[BUGFIX] Set datetime to current time for new records

As the TCA is cached, the default time is not always the current one.
Therefore set it via a hook in the FormEngine.

Resolves: #58649
Change-Id: I117773b8e19a2e5b23b5d7db3b2ab4c755d0c1bd
Reviewed-on: https://review.typo3.org/30178
Reviewed-by: Georg Ringer
Tested-by: Georg Ringer