Make a custom Random class

[rushingseas8]

• It would be nice for debugging to have a way to set the random seed (possibly in Generator)
• Unity's Random can be called externally, meaning depending on it can result in inconsistent behavior
• Propose adding a custom Random class that operates on System.Random under the hood, exposing a GetNext (or similar) method
• Using this custom Random class will allow for easy comparison or switching underlying implementations