By Cornelius Lysaght BBC horse racing correspondent Racegoers using hand sanitiser at Cheltenham RacecourseEnhanced hygiene measures used at jump racing’s Cheltenham Festival have been extended to all racecourses as the sport continues to hold fixtures. Regulator the British Horseracing Authority (BHA) provided all trainers, jockeys, racecourses and other race-day participants with information.The BHA said hand…