Add a "Set Sales" option

A set sales feature in the Splinterlands in-game market—without transaction fees—would be a huge win for the community 🎉. It would let players easily buy or sell full card sets in one go 🃏💼, saving time and effort ⏱️. New players could jump into the game with ready-to-play decks 🚀, while collectors and sellers would benefit from smoother, faster trades 🔄. Plus, no fees means better deals 💸 and more incentive to trade, helping the in-game economy grow naturally 📈.