====== getItemIcon ======


  * Parameters & Types:
    * itemid: number item type ID
    * Return value and type:
   * ErrorCode.OK
    * iconid: number item iconID
  * The main function of this method is to obtain the iconID of the item type icon
  * Specific use cases are as follows:


	local result,iconid = Customui:getItemIcon(itemid)