[BUGFIX] Persistent classes with more than five name parts in extbase

Resolve the table name of a corresponding class correctly when the name
has more than five parts.

This avoids unexpected SQL syntax errors when you have a full qualified
class names like "\Vendor\Extension\Domain\Model\Foo\Bar\Baz".

Resolves: #66425
Releases: master, 6.2
Change-Id: If31fe53bc34a3b2f2080732b2a0237d3480de79f
Reviewed-on: http://review.typo3.org/38749


Reviewed-by: Markus Klein <markus.klein@typo3.org>
Reviewed-by: Oliver Klee <typo3-coding@oliverklee.de>
Reviewed-by: Anja Leichsenring <aleichsenring@ab-softlab.de>
Tested-by: Anja Leichsenring <aleichsenring@ab-softlab.de>
Reviewed-by: Wouter Wolters <typo3@wouterwolters.nl>
Reviewed-by: Andreas Fernandez <typo3@scripting-base.de>
Reviewed-by: Jan Helke <typo3@helke.de>
Reviewed-by: Frank Nägler <typo3@naegler.net>
Tested-by: Frank Nägler <typo3@naegler.net>