By Sam Byford TOKYO (Reuters) – Asian shares tracked overnight Wall Street gains in early trading on Friday as fears of an economic slowdown cooled and sterling began to claw back recent losses following British Prime Minister Boris Johnson’s decision to resign. Japan’s Nikkei index was up 1.23% at 26,817.24 in morning trade, its highest mark since June 29th. MSCI’s broadest index of Asia-Pacific shares outside Japan gained 0.8% to its highest level in a week, and South Korea’s KOSPI index was up 1.18% and set for its best week in five months. All three major U.S. indices made gains overnight …