Updated Invoicing APIs

- Updated Model objects.
- Updated Samples.
- Updated Tests.

lib/PayPal/Api/TemplateSettingsMetadata.php

@@ -0,0 +1,41 @@
+<?php
+
+namespace PayPal\Api;
+
+use PayPal\Common\PayPalModel;
+
+/**
+ * Class TemplateSettingsMetadata
+ *
+ * Settings Metadata per field in template
+ *
+ * @package PayPal\Api
+ *
+ * @property bool hidden
+ */
+class TemplateSettingsMetadata extends PayPalModel
+{
+    /**
+     * Indicates whether this field should be hidden. default is false
+     *
+     * @param bool $hidden
+     * 
+     * @return $this
+     */
+    public function setHidden($hidden)
+    {
+        $this->hidden = $hidden;
+        return $this;
+    }
+
+    /**
+     * Indicates whether this field should be hidden. default is false
+     *
+     * @return bool
+     */
+    public function getHidden()
+    {
+        return $this->hidden;
+    }
+
+}