[TASK] Replace custom SiteBaseTestTrait implementation

To make frontend requests within functional tests a proper
frontend page setup is required, and TYPO3 uses internally
a `SiteBasedTestTrait` for own tests, which is not provided
in distrubtion packages.

Extension created and maintained there own versions, and in
some cased tried to make it working against multiple TYPO3
versions. Doing the same work again and again when having
multiple extension in the portfolio is a inefficient way.

To mitigate this, a dedicated package has been created now
to provide it in a central way and maintain it in one place.

This change replaces a custom implementation or the usage of
the TYPO3 implementation added with a source install of the
`EXT:core` system extension making the use easier.

The new package is added as development dependency and usage
throughout the functional tests are replaced and finaly the
custom implementation removed.

The package also provides a extended `FunctionalTestCase`,
which is also used to prepare for proper SiteSets based
functional frontend request testing by overriding a method
essential in this case to make it possible **not** to create
a `sys_template` record.

As a sideeffect we can now remove some phpstan error patterns,
which are properly defined and mitigated with the 3rd party
package.

Used command(s):

```shell
Build/Scripts/runTests.sh -p 8.1 -t 12 -s composer -- \
  require --dev \
  'sbuerk/typo3-site-based-test-trait':'^1.0.2 || ^2.0.1' \
&& Build/Scripts/runTests.sh -p 8.1 -t 12 -s composerUpdate \
&& Build/Scripts/runTests.sh -p 8.1 -t 12 -s cgl \
&& Build/Scripts/runTests.sh -p 8.1 -t 12 -s phpstanGenerateBaseline \
&& Build/Scripts/runTests.sh -p 8.2 -t 13 -s composerUpdate \
&& Build/Scripts/runTests.sh -p 8.2 -t 13 -s phpstanGenerateBaseline
```

Author: sbuerk

Build/phpstan/Core12/phpstan-baseline.neon

@@ -12,10 +12,10 @@
 use Psr\Log\NullLogger;
 use Ramsey\Uuid\Uuid;
 use RuntimeException;
+use SBUERK\TYPO3\Testing\TestCase\FunctionalTestCase;
 use Symfony\Component\DependencyInjection\Container;
 use TYPO3\CMS\Core\Information\Typo3Version;
 use TYPO3\CMS\Core\Utility\StringUtility;
-use TYPO3\TestingFramework\Core\Functional\FunctionalTestCase;
 use WebVision\Deepltranslate\Core\Client;
 use WebVision\Deepltranslate\Core\ClientInterface;
 use WebVision\Deepltranslate\Core\ConfigurationInterface;

Build/phpstan/Core13/phpstan-baseline.neon

@@ -6,11 +6,11 @@
 
 use PHPUnit\Framework\Attributes\IgnoreDeprecations;
 use PHPUnit\Framework\Attributes\Test;
+use SBUERK\TYPO3\Testing\SiteHandling\SiteBasedTestTrait;
 use TYPO3\CMS\Core\DataHandling\DataHandler;
 use TYPO3\CMS\Core\Localization\LanguageServiceFactory;
 use TYPO3\CMS\Core\Utility\GeneralUtility;
 use WebVision\Deepltranslate\Core\Tests\Functional\AbstractDeepLTestCase;
-use WebVision\Deepltranslate\Core\Tests\Functional\Fixtures\Traits\SiteBasedTestTrait;
 
 final class ContentElementsInContainerTest extends AbstractDeepLTestCase
 {
@@ -84,16 +84,16 @@ protected function setUp(): void
 
         $this->importCSVDataSet(__DIR__ . '/Fixtures/page_with_container.csv');
         $this->writeSiteConfiguration(
-            'acme',
-            $this->buildSiteConfiguration(1, '/', 'Home'),
-            [
+            identifier: 'acme',
+            site: $this->buildSiteConfiguration(rootPageId: 1),
+            languages: [
                 $this->buildDefaultLanguageConfiguration('EN', '/'),
                 $this->buildLanguageConfiguration('EB', '/eb/', ['EN'], 'strict'),
                 $this->buildLanguageConfiguration('DE', '/de/', ['EN'], 'strict'),
                 $this->buildLanguageConfiguration('BS', '/bs/', ['EN'], 'strict'),
-            ]
+            ],
         );
-        $this->setUpFrontendRootPage(1, [], []);
+        $this->setUpFrontendRootPage(pageId: 1);
 
         $this->setUpBackendUser(1);