AC-246: Update MFTF tests

Added seclector for Style icon in PB

Author: kieuphan2406

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

@@ -0,0 +1,13 @@
+<?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="urn:magento:mftf:Page/etc/SectionObject.xsd">
+    <section name="TinyMCESection">
+        <element name="Style" type="button" selector="button[title='Formats']"/>
+    </section>
+</sections>