EntityListenerResolver: Added support for inherited entity listeners

Consider the following entity listeners:

```php
class FileListener { ... }
class ImageListener extends FileListener { ... }
```

And entities:
```php

/**
 * @ORM\Entity
 * @ORM\EntityListeners({"FileListener"})
 */
class File { ... }

/**
 * @ORM\Entity
 * @ORM\EntityListeners({"ImageListener"})
 */
class Image extends File { ... }
```

The original implementation would fail while trying to resolve the `FileListener` with `Nette\DI\MissingServiceException: Multiple services of type FileListener found`.