MC-257: [Visual Merchandiser] Admin should be able to move assigned product position in the category by editing Position field in grid mode - move in the middle within same page

- added mftf tests

Author: jilu1

dev/tests/acceptance/tests/functional/Magento/FunctionalTest/Catalog/Section/StorefrontCategoryMainSection.xml

@@ -25,5 +25,6 @@
         <element name="productPrice" type="text" selector="div.price-box.price-final_price"/>
         <element name="categoryImage" type="text" selector=".category-image"/>
         <element name="emptyProductMessage" type="block" selector=".message.info.empty>div"/>
+        <element name="lineProductName" type="text" selector=".products.list.items.product-items li:nth-of-type({{line}}) .product-item-link" timeout="30" parameterized="true"/>
     </section>
 </sections>

dev/tests/acceptance/tests/functional/Magento/FunctionalTest/Catalog/Section/StorefrontCategoryTopToolbarSection.xml

@@ -0,0 +1,16 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<!--
+ /**
+  * Copyright © Magento, Inc. All rights reserved.
+  * See COPYING.txt for license details.
+  */
+-->
+
+<sections xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
+          xsi:noNamespaceSchemaLocation="../../../../../../vendor/magento/magento2-functional-testing-framework/src/Magento/FunctionalTestingFramework/Page/etc/SectionObject.xsd">
+    <section name="StorefrontCategoryTopToolbarSection">
+        <element name="gridMode" type="button" selector=".//*[@class='toolbar toolbar-products'][1]//*[@id='mode-grid']" timeout="30"/>
+        <element name="listMode" type="button" selector=".//*[@class='toolbar toolbar-products'][1]//*[@id='mode-list']" timeout="30"/>
+        <element name="sortByDropdown" type="select" selector=".//*[@class='toolbar toolbar-products'][1]//*[@id='sorter']" timeout="30"/>
+    </section>
+</sections>