Fix exception message to avoid coupling of stock management with catalog

Author: Volodymyr Kublytskyi

app/code/Magento/CatalogInventory/Model/StockStateProvider.php

@@ -160,7 +160,7 @@ public function checkQuoteItemQty(StockItemInterface $stockItem, $qty, $summaryQ
         }
 
         if (!$this->checkQty($stockItem, $summaryQty) || !$this->checkQty($stockItem, $qty)) {
-            $message = __('We don\'t have as many "%1" as you requested.', $stockItem->getProductName());
+            $message = __('The requested qty is not available');
             $result->setHasError(true)->setMessage($message)->setQuoteMessage($message)->setQuoteMessageIndex('qty');
             return $result;
         } else {
@@ -212,7 +212,7 @@ public function checkQuoteItemQty(StockItemInterface $stockItem, $qty, $summaryQ
                         }
                     } elseif ($stockItem->getShowDefaultNotificationMessage()) {
                         $result->setMessage(
-                            __('We don\'t have as many "%1" as you requested.', $stockItem->getProductName())
+                            __('The requested qty is not available')
                         );
                     }
                 }

dev/tests/integration/testsuite/Magento/Checkout/Controller/Cart/UpdateItemQtyTest.php

@@ -113,7 +113,7 @@ public function requestDataProvider(): array
                 'request' => ['qty' => 230],
                 'response' => [
                     'success' => false,
-                    'error_message' => 'We don\'t have as many "Simple Product" as you requested.']
+                    'error_message' => 'The requested qty is not available']
             ],
         ];
     }

dev/tests/integration/testsuite/Magento/Multishipping/Controller/Checkout/CheckItemsTest.php

@@ -163,7 +163,7 @@ public function requestDataProvider(): array
                 'request' => ['qty' => 101],
                 'response' => [
                     'success' => false,
-                    'error_message' => 'We don\'t have as many "Simple Product" as you requested.']
+                    'error_message' => 'The requested qty is not available']
             ],
             [
                 'request' => ['qty' => 230],

dev/tests/integration/testsuite/Magento/Quote/Model/QuoteTest.php

@@ -324,7 +324,7 @@ public function testAddProductUpdateItem()
         $this->assertEquals(1, $quote->getItemsQty());
 
         $this->expectException(\Magento\Framework\Exception\LocalizedException::class);
-        $this->expectExceptionMessage('We don\'t have as many "Simple Product" as you requested.');
+        $this->expectExceptionMessage('The requested qty is not available');
         $updateParams['qty'] = $productStockQty + 1;
         $quote->updateItem($updateParams['id'], $updateParams);
     }