Catalog API: one season, one channel, one language

The Catalog API can now download just the products of one or more seasons, and just the products published on a sales channel with the texts that channel shows, in the language you need.

Each sales channel can also have its own translations in every language — title, description, translatable attributes and SEO — on top of the product's own: your online store and a marketplace can show different German texts. Edit them on the product page by choosing the channel and the language, or read and write them through the API. Option names, like colors, can already differ by channel in the attribute settings, and the API now returns them too.