* Types and scaffolding for EIP-4844
This commit adds the EIP-4844 spec types, and fills in
scaffolding/boilerplate for the use of these types across the repo.
None of the actual EIP-4844 logic is introduced yet.
This follows the pattern used by @tersec when introducing Capella (#4276).
* use eth2-networks fork
* review feedback: add static check EIP4844_FORK_EPOCH == FAR_FUTURE_EPOCH
* review feedback: remove EIP4844 from /eth/v1/config/spec response
* Cleanup / review feedback
* Fix REST test
Etan Kissling
tersec
henridf