MC-35104: Tracking Page Builder content type

- Refactor: Access eventAttributes['menu_section'] as an array

Author: loginesta

app/code/Magento/PageBuilderAdminAnalytics/view/adminhtml/web/js/page-builder/events-mixin.js

@@ -45,7 +45,7 @@ define(['underscore'], function (_underscore) {
                     action: action,
                     widget: {
                         name: eventAttributes.form,
-                        type: eventAttributes.menu_section
+                        type: eventAttributes['menu_section']
                     },
                     feature: 'page-builder-tracker'
                 };