fix: update php version and optimize string operations

Updated the PHP version requirement from 8.0 to 8.1 in composer.json. Refactored the string operations functions in category.php and productList.php. Replaced the 'strpos' function with 'str_contains' for better readability and performance. Also replaced the usage of 'strpos' to check for string start with 'str_starts_with' for better readability. Fixed some strings formatting.

types/category.php

@@ -29,7 +29,7 @@
 
 // fallback url for a product, with NO category
 // this should never happen and is a configuration error
-if (strpos(QUI::getRequest()->getPathInfo(), '_p/') !== false) {
+if (str_contains(QUI::getRequest()->getPathInfo(), '_p/')) {
     $_REQUEST['_url'] = QUI::getRequest()->getPathInfo();
 
     if (strlen(URL_DIR) == 1) {
@@ -133,7 +133,7 @@
         }
 
         // if product url is with lang flag /en/
-        if (strpos($productUrl, '/', 1) === 3 && strpos($productUrl, '/_p/') === false) {
+        if (strpos($productUrl, '/', 1) === 3 && !str_contains($productUrl, '/_p/')) {
             $productUrl = mb_substr($productUrl, 3);
         }
 
@@ -304,7 +304,7 @@
     $fields = Products\Utils\Sortables::getSortableFieldsForSite($Site);
 
     foreach ($fields as $fieldId) {
-        if (strpos($fieldId, 'S') === 0) {
+        if (str_starts_with($fieldId, 'S')) {
             $title = QUI::getLocale()->get('quiqqer/products', 'sortable.' . mb_substr($fieldId, 1));
 
             $ProductList->addSort(
@@ -320,7 +320,7 @@
             continue;
         }
 
-        if (strpos($fieldId, 'F') === 0) {
+        if (str_starts_with($fieldId, 'F')) {
             try {
                 $fieldId = str_replace('F', '', $fieldId);
 
@@ -361,7 +361,7 @@
     }
 
     if ($hasFilter && !$ProductList->count()) {
-        // keine produkte -> weiterleitung zu main
+        // keine produkte → weiterleitung zu main
         $Redirect = new RedirectResponse($Site->getUrlRewritten());
         $Redirect->setStatusCode(Response::HTTP_SEE_OTHER);