[TASK] Streamline return tags in phpdocs

The TYPO3 Core currently has no guidline how to handle phpdoc
comments regarding @return annoations related to "void" and "null".

In practice, these annotations have no additional value if no additional
documentation is given.

With this change, the php-cs-fixer will remove any unnecessary linebreaks
within the comments above the @return annotation, as well as remove completely
empty phpdoc comments because the @return annotation is removed.

Please be aware, that once PSR-5 is accepted, this coding standard
within the TYPO3 Core will change again, where there are currently
some further proposal details like inheritance information.

Resolves: #80454
Releases: master
Change-Id: Ie969d720684c0a75919fe5addd1c36ef5b12eb04
Reviewed-on: https://review.typo3.org/51686


Reviewed-by: Nicole Cordes <typo3@cordes.co>
Tested-by: Nicole Cordes <typo3@cordes.co>
Reviewed-by: Benni Mack <benni@typo3.org>
Tested-by: Benni Mack <benni@typo3.org>