Add beacon API support for light client updates by range

[jimmygchen]

Description

Add support for the /eth/v1/beacon/light_client/updates API endpoint.

Beacon API spec: https://ethereum.github.io/beacon-APIs/#/Beacon/getLightClientUpdatesByRange

Additional Notes

There is an open issue for LightClientUpdatesByRange p2p support #3886 (Altair only). Probably make sense to merge that one first before starting this one.

[eserilev]

I believe #5545 included adding support for this api endpoint

see diff here:
https://github.com/sigp/lighthouse/pull/5545/files#diff-0aec0f89455da3fc1b452417ec63873cd95bd4ee3319e386233535544f47ab30R2489-R2502

so I think we should be good to close this one

[jimmygchen]

Nice! 🚀
Closing, thanks