Introduce high-level logic of new efficient transaction validation

To validate a 4844 transaction in the mempool, the verifier checks that each provided KZG commitment matches the
polynomial represented by the corresponding blob data.

     | d_1 | d_2 | d_3 | ... | d_4096 |    -> commitment

Before this patch, to do this validation, we reconstructed the commitment from the blob data (d_i above), and checked
it against the provided commitment. This was expensive because computing a commitment from blob data (even using
Lagrange basis) involves N scalar multiplications, where N is the number of field elements per blob.

Initial benchmarking showed that this was about 40ms for N=4096 which was deemed too expensive. For more details see:
             https://hackmd.io/@protolambda/eip-4844-implementer-notes#Optimizations
             protolambda/go-ethereum#4

In this patch, we speed this up by providing a KZG proof for each commitment. The verifier can check that proof to
ensure that the KZG commitment matches the polynomial represented by the corresponding blob data.

     | d_1 | d_2 | d_3 | ... | d_4096 |    -> commitment, proof

To do so, we evaluate the blob data polynomial at a random point `x` to get a value `y`. We then use the KZG proof to
ensure that the commited polynomial (i.e. the commitment) also evaluates to `y` at `x`. If the check passes, it means
that the KZG commitment matches the polynomial represented by the blob data.

This is significantly faster since evaluating the blob data polynomial at a random point using the Barycentric formula
can be done efficiently with only field operations (see https://hackmd.io/@vbuterin/barycentric_evaluation). Then,
verifying a KZG proof takes two pairing operations (which take about 0.6ms each). This brings the total verification
cost to about 2 ms per blob.

With some additional optimizations (using linear combination tricks as the ones linked above) we can batch all the
blobs together into a single efficient verification, and hence verify the entire transaction in 2.5 ms. The same
techniques can be used to efficiently verify blocks on the consensus side.

EIPS/eip-4844.md

@@ -344,6 +344,8 @@ class BlobTransactionNetworkWrapper(Container):
  tx: SignedBlobTransaction
  # KZGCommitment = Bytes48
  blob_kzgs: List[KZGCommitment, MAX_TX_WRAP_KZG_COMMITMENTS]
+ # KZGProofs = Bytes48
+ blob_proofs: List[KZGProof, MAX_TX_WRAP_KZG_COMMITMENTS]
  # BLSFieldElement = uint256
  blobs: List[Vector[BLSFieldElement, FIELD_ELEMENTS_PER_BLOB], LIMIT_BLOBS_PER_TX]
 ```
@@ -355,10 +357,19 @@ def validate_blob_transaction_wrapper(wrapper: BlobTransactionNetworkWrapper):
  versioned_hashes = wrapper.tx.message.blob_versioned_hashes
  commitments = wrapper.blob_kzgs
  blobs = wrapper.blobs
- assert len(versioned_hashes) == len(commitments) == len(blobs)
- for versioned_hash, commitment, blob in zip(versioned_hashes, commitments, blobs):
+ proofs = wrapper.blob_proofs
+
+ assert len(versioned_hashes) == len(commitments) == len(blobs) == len(proofs)
+ for versioned_hash, commitment, blob, proof in zip(versioned_hashes, commitments, blobs, proofs):
  # note: assert blob is not malformatted
- assert commitment == blob_to_kzg(blob)
+
+ # Get `x` point using Fiat-Shamir
+ x = hash_to_bls_field(commitment)
+ # Evaluate blob polynomial at `x`
+ y = evaluate_polynomial_in_evaluation_form(blob, x)
+ # Check that blob polynomial matches the `commitment` by verifying provided proof
+ assert verify_kzg_proof(commitment, x, y, proof)
+ # Finally check that the `versioned_hash` matches the `commitment`
  assert versioned_hash == kzg_to_versioned_hash(commitment)
 ```