[Ecommerce][Productindex][Elasticsearch] Mockup objects relation type is hardcoded to "objects"

[markus-moser]

Therefore asset and document relations do not work anymore.

https://github.com/pimcore/pimcore/blob/master/bundles/EcommerceFrameworkBundle/IndexService/ProductList/ElasticSearch/AbstractElasticSearch.php#L885

The type is stored in the store table but in the elasticsearch index only the IDs are stored. As we now use directly the data from elasticsearch instead of the store table the type information is now missing.

[fashxp]

also it seems that there is only the first relation loaded (hardcoded $relation[0]), not all...