fix for missing setvisible on FormItem

Author: Uroš Šavelj

src/XrmDefinitelyTyped/Resources/xrm.d.ts

@@ -1024,6 +1024,11 @@
      * Opens the specified form.
      */
     navigate(): void;
+
+    /**
+    * Sets a value that indicates whether the control is visible.
+    */
+    setVisible(visibility: boolean): void;
   }
 
   interface navigation {