Create codec for UpgradeConfig

[nytzuga]

Goal

Create a new codec to serialize all UpgradeConfig. This will be later used to hash and exchange in the network handshake.

This is a prerequisite to solve #268

Implementation idea

Implement a codec each type that is inside the UpdateConfig struct, the goal is to serialize the state into a deterministic vector of bytes.

The serialization must to be deterministic, otherwise when hashing the update config may not match.

The ultimate goal is to serialize and exchange it at handshake when connecting to a new node. This will be part of another ticket. The scope of this ticket is to serialize in a deterministic vector of bytes and to hash it.