Make it possible to encode to addresses when encoding blocks or transactions to json

[TheQuantumPhysicist]

In #1155, we serialize using serde_json. However, while we can serialize destinations and ids to hex, some of these elements are better serialized to a proper readable address. The problem is that the serialization of these elements depends on chain config, and serde_json doesn’t seem to have a way to accept a state, such as chain config.
We would like to avoid having to use a global variable that stores chain config for this.