Clean up unsigned integer types across HotShot

[elliedavidson]

There are many parts in HotShot where we do not use a consistent uint size. Sometimes we use usize, other times u64, etc. This is particularly noticeable in the HotShot config and NetworkConfig. We should clean these up to make them consistent. Many places don't have a reason to be using a usize versus a u64, for example. Sometimes we are representing the same data in two different types across HotShot.