Typed Stores

[JamesArruda]

Stores are untyped in SimPy, but they should be able to be typed here.

Either PR simpy or subclass.

[JamesArruda]

Idea: Just UPSTAGE stores can hold the type information, which might be accessible from a generic on the store.

How to get that type information into UP.Get (and then from get_value is uncertain.