Suni Lee did it big for her 23rd birthday ... making her way to Turks & Caicos with her friends for a poolside party -- and the views were gold-medal worthy!! The Team USA gymnast -- whose special day is March 9 -- documented the trip on social media ... showing the group rocking "I heart Suni Lee" shirts and surprising her with "happy birthday" balloons. But the highlight of the trip was apparently lounging by the water ... which turned into the backdrop for some TikToks. Suni and her crew