Return specified default value in EntityContext

With the current implementation the default value is ignored when the EntityContext was created from an array.

src/View/Form/EntityContext.php

@@ -262,7 +262,7 @@ public function val($field, $options = [])
         if (is_array($entity)) {
             $key = array_pop($parts);
 
-            return isset($entity[$key]) ? $entity[$key] : null;
+            return isset($entity[$key]) ? $entity[$key] : $options['default'];
         }
 
         return null;