Add a feature flag

[MAILPOET-1709]

assets/js/src/newsletter_editor/blocks/products.js

@@ -592,6 +592,9 @@ Module.PostsWidgetView = base.WidgetView.extend({
 });
 
 App.on('before:start', function beforeStartApp(BeforeStartApp) {
+  if (_.isEmpty(window.config.displayWcProductsWidget)) {
+    return;
+  }
   BeforeStartApp.registerBlockType('products', {
     blockModel: Module.PostsBlockModel,
     blockView: Module.PostsBlockView,