====== getBlockIcon ======


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


	local result,iconid = Customui:getBlockIcon(blockid)