Improve spread rate limiting (SpreadShaper.cs)

[BlossomiShymae]

I think the current spread limiting strategy for AlgorithmicLimiter can be improved upon. With how it works currently, it is set to be overly safe for the delay coefficient (3 * Math.Pow(progress, 2)). Unfortunately, a small percentage of requests (~0-5%) for a given limit is left unused. u.u

It works for now but it can probably be changed for the better. Setting the delay coefficient any lower will just trigger the WarningLimiterException (for smaller or larger rate limits I don't remember...), not what we wantsies.

See lines of code.

[BlossomiShymae]

I think I should just make it queue-based and have the web request be sent based on available time before the limit bucket resets.