MC-3393: Create/update MFTF tests for hiding content blocks

- assert cant use button item in stage after disabling

Author: anthoula

app/code/Magento/PageBuilder/Test/Mftf/Test/AdminPageBuilderButtonGroupTests.xml

@@ -1717,6 +1717,7 @@
         <!-- Validate content type remains disabled after save -->
         <comment userInput="Validate content type remains disabled after save" stepKey="commentValidateHiddenStage"/>
         <seeElement selector="{{ButtonGroupOnStage.hidden('1')}}" stepKey="waitForContentTypeHidden" />
+        <seeElement selector="{{ButtonItemOnStage.hidden('1')}}" stepKey="waitForContentTypeHiddenButtonItem" />
         <!-- Validate store front -->
         <comment userInput="Validate content type is disabled on storefront" stepKey="commentValidateHiddenStorefront"/>
         <openNewTab stepKey="openNewTab" />