Add attributes from Subarticles to Selections

corresponding https://forum.arcavias.com/viewtopic.php?f=12&t=314

works in my demo, please give it a try. 
I actually think the changes in  client/html/src/Client/Html/Catalog/Detail/Basket/Selection/Default.php will make more sense in  client/html/src/Client/Html/Catalog/Detail/Additional/Attribute/Default.php.