Move error generation method to abstract controller

I want those methods to be moved from the AbstractActionController to AbstractController since they're important even if you want to dispatch directly instead of having many actions (which is what i'm doing). 

Otherwise, i'll have to create my own extension of AbstractController or a trait and use it in all my project controllers, which would make necessary to have a "base" module.

The tests will still pass because the methods will be still be available in AbstractActionController, since it is an extension of AbstractController. I chose not to move the notFoundAction since it is an action and should stay in AbstractActionController.

With this update, we'll be able to:

```php
@var MvcEvent $e
$e->setResponse($this->createHttpNotFoundModel($response));
```