Add support for weapon and armor traits for Keyforge

[ShaneK]

In Keyforge there aren't actually specific weapons, rather there's generic bases with base stats and traits you can stack on top of them.

Emporium currently supports Craftsmanship, which is similar to traits, but different and varied enough that I don't feel comfortable tacking them on to Craftsmanship. Would be cool to support traits, at least if using Keyforge.