It has been 25 years since Danish dance-pop group band Aqua hit it big with their notorious hit “Barbie Girl” — and lead vocalist Lene Nystrøm still has some mixed feelings about the song that continues to cause a phenomenon. “I would be compared with ‘Barbie Girl’ all the time,” explains Nystrøm, 48, while sitting next to her color-coordinated bandmates Rene Dif and …