leaderboard item sort error

[falcao-g]

Description of the bug

the /leaderboard item has a issue when the user sends a item name valid but different from the item key in the items.jsom, to fix this we need to first get the item key using getItem() and afterwards verify that the key is valid (!== undefined)and finally send the query with the item key given

Steps to reproduce

use /leaderboard item and input im the item field "pedra" for example, falbot executes the command because pedra is a valid item (rock), but it sends the query to mongodb with the text the user gave it

Media, if necessary

No response