[BUGFIX] Do not use "newlyCreated" workaround in FAL

With PSR-14 events, it is now easier to detect newly created metadata records.

For the time being, the pseudo-field "newlyCreated" is removed and
the current check is made against "crdate".

In addition, a unnecessary unit tests was removed.

Resolves: #89020
Releases: master
Change-Id: Ifc5e0e0faee6e3b6f7130c2387abbe6e6992109e
Reviewed-on: https://review.typo3.org/c/Packages/TYPO3.CMS/+/63874


Tested-by: Susanne Moog <look@susi.dev>
Tested-by: Georg Ringer <georg.ringer@gmail.com>
Reviewed-by: Susanne Moog <look@susi.dev>
Reviewed-by: Georg Ringer <georg.ringer@gmail.com>