[BUGFIX] Streamline offsetGet and offsetExist in Record object

Array access of `uid` and `pid` has been enabled, therefore
offsetExist() needs to return TRUE for those fields, too.

Resolves: #104758
Releases: main
Change-Id: I5d2b0ba67e91daa258702431cbbcdcc2427bf68b
Reviewed-on: https://review.typo3.org/c/Packages/TYPO3.CMS/+/85805


Tested-by: Oliver Bartsch <bo@cedev.de>
Reviewed-by: Benni Mack <benni@typo3.org>
Tested-by: core-ci <typo3@b13.com>
Reviewed-by: Christian Kuhn <lolli@schwarzbu.ch>
Reviewed-by: Oliver Bartsch <bo@cedev.de>
Tested-by: Christian Kuhn <lolli@schwarzbu.ch>
Tested-by: Benni Mack <benni@typo3.org>