[CORE] Cataclysm - TimeDuration::ToString

[LambdaSix]

TimeDuration::ToString() needs an overhaul to print more human-friendly timespans

ie.

TimeDuration.FromWeeks(1).AddDays(2).AddHours(3).AddMinutes(40);

should resolve to the string "1 week, 2 days, 4 hours, 40 minutes"