[TASK] PSR-12: Add empty lines at the beginning of PHP files

This change adds two changes
        'blank_line_after_opening_tag' => true,
        'single_trait_insert_per_statement' => true,

to our PHP-CS Fixer configuration, adopting more rules related
to PSR-12.

Resolves: #91020
Releases: master
Change-Id: I180b2cbceb077911bddeb42d9f131e5b32244ed2
Reviewed-on: https://review.typo3.org/c/Packages/TYPO3.CMS/+/64158

Tested-by: Josef Glatz <josefglatz@gmail.com>
Tested-by: Oliver Bartsch <bo@cedev.de>
Tested-by: Alexander Schnitzler <git@alexanderschnitzler.de>
Tested-by: Andreas Fernandez <a.fernandez@scripting-base.de>
Tested-by: TYPO3com <noreply@typo3.com>
Reviewed-by: Josef Glatz <josefglatz@gmail.com>
Reviewed-by: Oliver Bartsch <bo@cedev.de>
Reviewed-by: Alexander Schnitzler <git@alexanderschnitzler.de>
Reviewed-by: Andreas Fernandez <a.fernandez@scripting-base.de>

Build/.php_cs

@@ -56,6 +56,7 @@ return PhpCsFixer\Config::create()
         '@DoctrineAnnotation' => true,
         '@PSR2' => true,
         'array_syntax' => ['syntax' => 'short'],
+        'blank_line_after_opening_tag' => true,
         'cast_spaces' => ['space' => 'none'],
         'concat_space' => ['spacing' => 'one'],
         'declare_equal_normalize' => ['space' => 'none'],
@@ -94,6 +95,7 @@ return PhpCsFixer\Config::create()
         'phpdoc_types_order' => ['null_adjustment' => 'always_last', 'sort_algorithm' => 'none'],
         'return_type_declaration' => ['space_before' => 'none'],
         'single_quote' => true,
+        'single_trait_insert_per_statement' => true,
         'whitespace_after_comma_in_array' => true,
     ])
     ->setFinder($finder);

Build/Scripts/composer/InstallerScripts.php

 <?php
+
 declare(strict_types=1);
 namespace TYPO3\CMS\Composer\Scripts;
 

typo3/sysext/about/Classes/Controller/AboutController.php

 <?php
+
 namespace TYPO3\CMS\About\Controller;
 
 /*

typo3/sysext/about/ext_emconf.php

 <?php
+
 $EM_CONF[$_EXTKEY] = [
     'title' => 'Help>About',
     'description' => 'Shows info about TYPO3, installed extensions and a separate module for available modules.',

typo3/sysext/about/ext_tables.php

 <?php
+
 defined('TYPO3_MODE') or die();
 
 \TYPO3\CMS\Core\Utility\ExtensionManagementUtility::addModule(

typo3/sysext/adminpanel/Classes/Controller/AjaxController.php

 <?php
+
 declare(strict_types=1);
 
 namespace TYPO3\CMS\Adminpanel\Controller;

typo3/sysext/adminpanel/Classes/Controller/MainController.php

 <?php
+
 declare(strict_types=1);
 
 namespace TYPO3\CMS\Adminpanel\Controller;

typo3/sysext/adminpanel/Classes/Exceptions/InvalidConfigurationException.php

 <?php
+
 declare(strict_types=1);
 
 namespace TYPO3\CMS\Adminpanel\Exceptions;

typo3/sysext/adminpanel/Classes/Log/DoctrineSqlLogger.php

 <?php
+
 declare(strict_types=1);
 
 namespace TYPO3\CMS\Adminpanel\Log;

typo3/sysext/adminpanel/Classes/Log/InMemoryLogWriter.php

 <?php
+
 declare(strict_types=1);
 
 namespace TYPO3\CMS\Adminpanel\Log;

typo3/sysext/adminpanel/Classes/Middleware/AdminPanelDataPersister.php

 <?php
+
 declare(strict_types=1);
 
 namespace TYPO3\CMS\Adminpanel\Middleware;

typo3/sysext/adminpanel/Classes/Middleware/AdminPanelInitiator.php

 <?php
+
 declare(strict_types=1);
 
 namespace TYPO3\CMS\Adminpanel\Middleware;

typo3/sysext/adminpanel/Classes/Middleware/AdminPanelRenderer.php

 <?php
+
 declare(strict_types=1);
 
 namespace TYPO3\CMS\Adminpanel\Middleware;

typo3/sysext/adminpanel/Classes/Middleware/SqlLogging.php

 <?php
+
 declare(strict_types=1);
 
 namespace TYPO3\CMS\Adminpanel\Middleware;

typo3/sysext/adminpanel/Classes/ModuleApi/AbstractModule.php

 <?php
+
 declare(strict_types=1);
 
 namespace TYPO3\CMS\Adminpanel\ModuleApi;

typo3/sysext/adminpanel/Classes/ModuleApi/AbstractSubModule.php

 <?php
+
 declare(strict_types=1);
 
 namespace TYPO3\CMS\Adminpanel\ModuleApi;

typo3/sysext/adminpanel/Classes/ModuleApi/ConfigurableInterface.php

 <?php
+
 declare(strict_types=1);
 
 namespace TYPO3\CMS\Adminpanel\ModuleApi;

typo3/sysext/adminpanel/Classes/ModuleApi/ContentProviderInterface.php

 <?php
+
 declare(strict_types=1);
 
 namespace TYPO3\CMS\Adminpanel\ModuleApi;

typo3/sysext/adminpanel/Classes/ModuleApi/DataProviderInterface.php

 <?php
+
 declare(strict_types=1);
 
 namespace TYPO3\CMS\Adminpanel\ModuleApi;

typo3/sysext/adminpanel/Classes/ModuleApi/InitializableInterface.php

 <?php
+
 declare(strict_types=1);
 
 namespace TYPO3\CMS\Adminpanel\ModuleApi;