exp/lighthorizon, xdr: Rename `CheckpointIndex` to better reflect its capabilty.#4510

Merged

Shaptic merged 3 commits intostellar:lighthorizonfrom Shaptic:lighthorizon_renameIndex

Aug 8, 2022

+185-185

Commits on Aug 5, 2022

Commits on Aug 8, 2022

More checkpoint -> bitmap renames
Shaptic
committed