[BUGFIX] Pid property not set after insert

After adding and persisting a new object, its uid property is set,
the same should happen for its pid property. This way the caller
can get to know where the object ended up being stored.

Resolves: #60544
Releases: master, 6.2
Change-Id: Ibd11918c06b52deac69a8c3b83c454e3f24462a8
Reviewed-on: http://review.typo3.org/35474


Reviewed-by: Michael Oehlhof <typo3@oehlhof.de>
Reviewed-by: Oliver Klee <typo3-coding@oliverklee.de>
Reviewed-by: Benjamin Mack <benni@typo3.org>
Reviewed-by: Steffen Müller <typo3@t3node.com>
Tested-by: Steffen Müller <typo3@t3node.com>
Reviewed-by: Anja Leichsenring <aleichsenring@ab-softlab.de>
Tested-by: Anja Leichsenring <aleichsenring@ab-softlab.de>