MAGETWO-87243: Unskip failing MFTF tests for WYSIWYG

- Added wait for checkbox and added story for Row Test

Author: kieuphan2406

dev/tests/acceptance/tests/functional/Magento/FunctionalTest/Config/ActionGroup/ConfigWYSIWYGActionGroup.xml

@@ -13,6 +13,7 @@
         <waitForPageLoad stepKey="wait1"/>
         <conditionalClick stepKey="expandWYSIWYGOptions" selector="{{ContentManagementSection.WYSIWYGOptions}}" dependentSelector="{{ContentManagementSection.CheckIfTabExpand}}" visible="true" />
         <waitForElementVisible selector="{{ContentManagementSection.EnableWYSIWYG}}" stepKey="waitForEnableWYSIWYGDropdown1" />
+        <waitForElementVisible  selector="{{ContentManagementSection.EnableSystemValue}}" stepKey="waitForUseSystemValueVisible"/>
         <uncheckOption selector="{{ContentManagementSection.EnableSystemValue}}" stepKey="uncheckUseSystemValue"/>
         <selectOption selector="{{ContentManagementSection.EnableWYSIWYG}}" userInput="Enabled by Default" stepKey="selectOption1"/>
         <click selector="{{ContentManagementSection.WYSIWYGOptions}}" stepKey="collapseWYSIWYGOptions" />