Stemming from this discussion

We should probably do a significant refactor to the way we handle forks. Namely, what this would involve would be:

• Having a way to, having a fork, obtain the next fork
• Having a way to obtain the latest fork out of a set
• Rather than having a separate field for the activation timestamps/block numbers of each fork, having an array that's indexed by the fork number

This would make obtaining the next fork for a given chain config, as well as the latest fork, much easier; as well as making the code more maintainable in the long run.