Fix docblocks to show correct Mage_Sales_Model_Order_Invoice return / var type (#5145)

* Fix docblocks to show correct return / var type

* Remove baseline entry for method register() missing

In fixing the annotations for Mage_Sales_Model_Order_Invoice,
PHPStan can now correctly find the register() method.

Author: ajbonner

.phpstan.dist.baseline.neon

@@ -1362,12 +1362,6 @@ parameters:
 			count: 1
 			path: app/code/core/Mage/Checkout/controllers/CartController.php
 
-		-
-			rawMessage: 'Call to an undefined method Mage_Sales_Model_Service_Order::register().'
-			identifier: method.notFound
-			count: 1
-			path: app/code/core/Mage/Checkout/controllers/OnepageController.php
-
 		-
 			rawMessage: 'Parameter #1 $attr of method Mage_ConfigurableSwatches_Helper_Data::attrIsSwatchType() expects int|Mage_Eav_Model_Attribute, Mage_Catalog_Model_Resource_Eav_Attribute given.'
 			identifier: argument.type

app/code/core/Mage/Checkout/controllers/OnepageController.php

@@ -544,7 +544,7 @@ protected function _getOrder()
     /**
      * Create invoice
      *
-     * @return Mage_Sales_Model_Service_Order
+     * @return Mage_Sales_Model_Order_Invoice
      * @throws Mage_Core_Exception
      * @throws Mage_Payment_Model_Info_Exception
      */
@@ -555,7 +555,7 @@ protected function _initInvoice()
             $items[$item->getId()] = $item->getQtyOrdered();
         }
 
-        /** @var Mage_Sales_Model_Service_Order $invoice */
+        /** @var Mage_Sales_Model_Order_Invoice $invoice */
         $invoice = Mage::getModel('sales/service_order', $this->_getOrder())->prepareInvoice($items);
         $invoice->setEmailSent(true)->register();