* adopt LC REST API with v0 suffix (without proofs)
Adopts the light client data REST API used by Lodestar as defined in
https://github.com/ethereum/beacon-APIs/pull/181 with a v0 suffix.
Requests:
- `/eth/v0/beacon/light_client/bootstrap/{block_root}`
- `/eth/v0/beacon/light_client/updates?start_period={start_period}&count={count}`
- `/eth/v0/beacon/light_client/finality_update`
- `/eth/v0/beacon/light_client/optimistic_update`
HTTP Server-Sent Events (SSE):
- `light_client_finality_update_v0`
- `light_client_optimistic_update_v0`
More work is needed to adopt the proofs endpoint, it is not included.
* initialize event queues
* register event topics
Etan Kissling