Change default sort option on CMS productlist and product group plugins to match product manager default sort

By Default the product manager expects you to manage the sequence of groups and products within groups and makes it easy to reorder items by dragging and dropping them.

However, the product list item plugin and the product group plugins have defaults of "alphabetical" sorting which means that by default the two are different.

We should change the plugin defaults, and make sure the gallery sites have default sort of non-alphabetical