[Feature Request] List shops selling item, and what price

[NaruZosa]

This feature currently exists on the addstar server, as a custom plugin they've made, the source of which is here: https://github.com/AddstarMC/MarketSearch

Essentially, it allows you to enter /ms find [itemname] and it'll return a list of players selling the item entered from cheapest to most expensive. The command also supports item data such as enchantments, and /ms sell [itemname] to find players to sell to.

This feature would be extremely useful for large servers to save players a lot of time searching through all stores selling a specific item to find the cheapest.