unit - A unit to query; only valid for 'player' or the unit currently being inspected (string, unitID)
slot - An inventory slot number, as can be obtained from GetInventorySlotInfo (number, inventoryID)
nameOnly - True to omit much of the item's information (stat bonuses, sockets, and binding) from the tooltip; false to show all of the item's information (boolean)
Returns:
hasItem - 1 if the unit has an item in the given slot; otherwise nil (number, 1nil)
hasCooldown - 1 if the item is currently on cooldown; otherwise nil (number, 1nil)
repairCost - Cost to repair the item (in copper, ignoring faction discounts) (number)
