MAGETWO-57255: Eliminate @escapeNotVerified in Widget Module

- updated the templates

Author: buskamuza

app/code/Magento/Widget/view/adminhtml/templates/catalog/category/widget/tree.phtml

@@ -79,7 +79,7 @@ jQuery(function()
                 // Add empty node to reset category filter
                 if(!emptyNodeAdded) {
                     var empty = Object.clone(_node);
-                    empty.text = '<?php /* @escapeNotVerified */ echo __('None') ?>';
+                    empty.text = '<?php echo $block->escapeJs($block->escapeHtml(__('None'))); ?>';
                     empty.children = [];
                     empty.id = 'none';
                     empty.path = '1/none';

app/code/Magento/Widget/view/adminhtml/templates/instance/edit/layout.phtml

@@ -10,7 +10,7 @@
 
 ?>
 <fieldset class="fieldset">
-    <legend class="legend"><span><?php /* @escapeNotVerified */ echo __('Layout Updates') ?></span></legend>
+    <legend class="legend"><span><?php echo $block->escapeHtml(__('Layout Updates')); ?></span></legend>
     <br />
     <div class="widget-layout-updates">
         <div id="page_group_container"></div>