Ethan Reesor authored Mar 05, 2022 and Dennis B committed Mar 05, 2022

- Closes AC-1099.
- Adds an index chain for every transaction (main, signature) and anchor chain.
- For the root anchor chain, entries are {root anchor chain height, block index}.
- For the other chains, entries are {chain height, index of anchor inserted into the root anchor chain}.
- Index chains are used to construct transaction proofs.
- There is no API yet beyond the basic chain API.