feat: replace cookie to store tracking code with native php session

public/typo3conf/ext/ep_theme/Classes/DataProcessing/ContextProcessor.php

@@ -64,9 +64,6 @@ class ContextProcessor implements DataProcessorInterface
         }
         if ($data['tx_eptheme_context_pacode']) {
             $processedData['context']['paCode'] = $data['tx_eptheme_context_pacode'];
-// Disabled, not working anyways, reseller subdomains are not registered since TYPO3 10.*
-//        } elseif ($resellerData = $this->getResellerData()) {
-//            $processedData['context']['paCode'] = $resellerData['paCode'];
         } elseif ($paCode = $this->getPaCodeFromRequest()) {
             $processedData['context']['paCode'] = $paCode;
         }