This PR changes class attributes resolution fetching parent classes attributes as well as current class attributes.

This allows the developer to factorize attributes declarations parent classes.

For example if we want every data to be mapped with SnakeCaseMapper, we currently need to declare #[MapName(SnakeCaseMapper::class)] on every single Data class.

With this PR, we can declare a BaseData with the mapper and every child class with inherit with the mapper.

#[MapName(SnakeCaseMapper::class)]
abstract class BaseData extends Data {}

class MyData extends BaseData {
    public function __construct(
        public string $firstName,
    ) {}
}

MyData::from(['first_name' => 'John']); // work as expected

In case the attribute is redeclared in child class, the child attribute has higher priority (parents attributes are push at the end of the collection).