Add ids from Horizon where applicable

[Isaiah-Turner]

What

We need to implement the horizon ids for ledgers, transactions, operations, and offers. Horizon uses an internal ToID package, which we should replicate.

Why

Right now, the ETL cannot output identification that is consistent with Horizon’s ids. We would like ecosystem wide consistency so that users who build off different ingestion engines see the same results, so we need to implement Horizon's id system.