Jan 7 (Reuters) - GameStop on Wednesday unveiled a compensation package worth roughly $35 billion for CEO Ryan Cohen, hinging on a turnaround that requires him to lift the struggling videogame retailer's ​market value more than tenfold and sharply boost its profit. Hitting the targets will require a significant ‌shift at GameStop, as the brick-and-mortar store operator has been losing millions in revenue in recent years with gamers turning to the ‌web for purchases. The company's annual revenue has plum ...