Kzg crate

This crate contains functions related to kzg commitment that is used for 4844 blobs.

There are 3 methods that are used by era from this crate:

• pubdata_to_blob_commitments - computes the blob commitments for given pub data
• KzgInfo - holds all the methods for converting bytes into blobs
• ZK_SYNC_BYTES_PER_BLOB - information on how much data is stored per blob.

lib.rs:

Implementation based on https://github.com/ethereum/consensus-specs/blob/86fb82b221474cc89387fa6436806507b3849d88/specs/deneb/polynomial-commitments.md