MC-3475: Create MFTF Tests

- Adding tests for button same width in tab & column when resizing
- Adding supporting tab element

Author: dhaecker

app/code/Magento/PageBuilder/Test/Mftf/Section/PageBuilderTabsSection.xml

@@ -60,6 +60,7 @@
         <element name="tabColumnContent" type="button" selector="//div[contains(@class,'pagebuilder-tabs')]//div[contains(@class, 'pagebuilder-column-group')]"/>
     </section>
     <section name="TabOnStorefront">
+        <element name="all" type="button" selector="[data-role=\'tab-item\']"/>
         <element name="tabHeader" type="button" selector="(//li[contains(@role, 'tab')])[{{arg1}}]" parameterized="true"/>
         <element name="tabHeaderItemActive" type="button" selector="(//div[@data-role='tabs']//descendant::*[@role='tablist'])/li[{{arg1}}][contains(@class, 'ui-state-active')]" parameterized="true"/>
         <element name="tabPanel" type="button" selector="(//div[@class='tabs-content']//div[@role='tabpanel'])[{{arg1}}]" parameterized="true"/>