Trims and truncates a string to the specified length in runes (Unicode code points) and appends an ellipsis if truncated. Multi-byte characters such as emoji or CJK ideographs are never split in the middle.
lo.Ellipsis(" Lorem Ipsum ", 5) // "Lo..." str = lo.Ellipsis("Lorem Ipsum", 100) // "Lorem Ipsum" str = lo.Ellipsis("Lorem Ipsum", 3) // "..." str = lo.Ellipsis("hello 世界! 你好", 8) // "hello..." str = lo.Ellipsis("🏠🐶🐱🌟", 4) // "🏠🐶🐱🌟"