Add simple response method to view

[pchalupa]

Describe your feature request

After some actions where We don't need to response with data, there could be handy method witch basically render only some sort of standardized format like {"status": "ok"} or something like that. Sou the general workflow should looks like that:

action
$this->view->responseOk();
return

Method name is not definitely given, it can be differ. There could be another method with same purpose with inverse meaning.