BOSTON — A foundation set up by a Boston Marathon bombing survivor is donating its first artificial limb.The Heather Abbott Foundation was established by Abbott, who lost a leg in the 2013 terrorist attacks at the marathon finish line. She says its first prosthesis recipient will be a 26-year-old woman from Walpole, Massachusetts.Hillary Cohen will be fitted with a custom-made leg Monday at the office of her prosthetics specialist in Newton.