[TASK] composer require --dev phpstan/phpstan

This commit introduces a development requirement to
phpstan/phpstan to enable static code analysis.

A basic configuration file has been added as well to
identify most basic errors in the TYPO3 code base.

Releases: master
Resolves: #90097
Change-Id: I87e11eca6296864fdd7ba8cd109a23b82c27f641
Reviewed-on: https://review.typo3.org/c/Packages/TYPO3.CMS/+/62851


Tested-by: TYPO3com <noreply@typo3.com>
Tested-by: Steffen Frese <steffenf14@gmail.com>
Tested-by: Felix P. <f.pachowsky@neusta.de>
Tested-by: Sascha Egerer <sascha@sascha-egerer.de>
Tested-by: Frank Nägler <frank.naegler@typo3.org>
Reviewed-by: Oliver Klee <typo3-coding@oliverklee.de>
Reviewed-by: Steffen Frese <steffenf14@gmail.com>
Reviewed-by: Felix P. <f.pachowsky@neusta.de>
Reviewed-by: Sascha Egerer <sascha@sascha-egerer.de>
Reviewed-by: Jörg Bösche <typo3@joergboesche.de>
Reviewed-by: Frank Nägler <frank.naegler@typo3.org>