Goal: Implement type `CheckRepeatedChars<T>` which will return whether type `T` contains a duplicated member. Source challenge: https://github.com/type-challenges/type-challenges/tree/main/questions/27958-medium-checkrepeatedtuple Reference explanation: https://github.com/ghaiklor/type-challenges-solutions/blob/main/en/medium-checkrepeatedtuple.md