ATLANTA — Amid intense scrutiny and opposition, University of Pennsylvania swimmer Lia Thomas on Thursday became the first transgender athlete to win a Division I collegiate national championship. Thomas, a fifth-year senior and transgender woman, propelled past Olympic swimmers to place first in the 500-yard freestyle at the NCAA D1 Women’s Swimming and Diving National Championship at Georgia Institute of Technology. Thomas finished the race in 4:33.24, about three seconds faster than her season best, and maintaining her spot as the top swimmer in the nation among collegiate women in the 500 …