[TASK] Use php-cs-fixer directly (#152)

This change removes the package "typo3/coding-standards" in favour of
"friendsofphp/php-cs-fixer". There is no need to use this proxy package.

Instead, we define the needed rules directly. As we stick zu the PER-CS
standard (the successor of PSR-12) we pin the rules to the PER-CS 1
ruleset. Additionally, we opt in for some already implemented PER-CS 2
rules to avoid too much style changes already available in the codebase.

With the pinning to defined rules we ensure that updates of php-cs-fixer
does not "break" the currently used styles locally or in CI. Changes in
the defined rules can therefore be done explicitly.

resources/config/typo3-guides.php

@@ -4,11 +4,10 @@
 
 use phpDocumentor\Guides\Cli\Command\Run;
 use Symfony\Component\DependencyInjection\Loader\Configurator\ContainerConfigurator;
+use T3Docs\GuidesExtension\Command\RunDecorator;
 
 use function Symfony\Component\DependencyInjection\Loader\Configurator\service;
 
-use T3Docs\GuidesExtension\Command\RunDecorator;
-
 return static function (ContainerConfigurator $container): void {
     $container->services()
         ->defaults()