[TASK] Update coding styleguide to PER + additional configs

This change adapts our coding guidelines
and rules with PHP-CS-Fixer, allowing for
* PER (a.k.a. PSR-12)
* no_useless_nullsafe_operator (only use nullsafe if allowed)
* only single-spaces in arrays

This effectively adapts our code base
* use "public const" instead of "const" where visibility is not defined
* one whitespace between "declare()" and "namespace" declarations
* Use (float) instead of (double) casting
* Additional space in annonymous classes (PER)
* grouped "use" statements (classes, function, constants)
* only one space between items in array lists
* Use (bool) instead of (boolean)

Resolves: #98585
Releases: main, 11.5
Change-Id: Idb83729d0e4f9dc3c41e4dc5346dab77e6fbce84
Reviewed-on: https://review.typo3.org/c/Packages/TYPO3.CMS/+/76100


Tested-by: core-ci <typo3@b13.com>
Tested-by: Stefan Bürk <stefan@buerk.tech>
Tested-by: Christian Kuhn <lolli@schwarzbu.ch>
Reviewed-by: Stefan Bürk <stefan@buerk.tech>
Reviewed-by: Christian Kuhn...