Добавлен QueryRelationDataProvider

// Используем QueryRelationDataProvider для пагинации
$qrm = QueryRelationManager::select(City::class, 'c')
    ->withMultiple('addresses', Address::class, 'a', 'c', 'city_id', 'id');

$dataProvider = new QueryRelationDataProvider([
    'queryRelationManager' => $qrm,
    'pagination' => [
        'pageSize' => 2,
        'page' => 0,
    ],
]);

print_r($dataProvider->getModels());
/*Array
(
    [0] => Array
        (
            [id] => 1
            [name] => Moscow
            [addresses] => Array
                (
                    [0] => Array
                        (
                            [id] => 2
                            [city_id] => 1
                            [name] => Schipok st., 1
                        )

                    [1] => Array
                        (
                            [id] => 1
                            [city_id] => 1
                            [name] => Tverskaya st., 7
                        )

                )

        )

    [1] => Array
        (
            [id] => 2
            [name] => St. Petersburg
            [addresses] => Array
                (
                    [0] => Array
                        (
                            [id] => 4
                            [city_id] => 2
                            [name] => Galernaya st., 3
                        )

                    [1] => Array
                        (
                            [id] => 3
                            [city_id] => 2
                            [name] => Mayakovskogo st., 12
                        )

                )

        )

)*/