client: add getBlobsV1 to the client to support CL blob import

[g11tech]

ref:

• Define engine_getBlobsV1 ethereum/execution-apis#559

TODO: add to spec test

[jochem-brouwer]

Strong support for the API since we need to bring bandwidth requirements of a running a node down 😄

Two comments.

[codecov]

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blockchain	83.49% <ø> (?)
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common	89.85% <ø> (?)
genesis	0.00% <ø> (?)
tx	?
util	70.93% <ø> (?)
wallet	?

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[jochem-brouwer]

The spec says:

The fields are encoded as follows:

- `blob`: `DATA` - `FIELD_ELEMENTS_PER_BLOB * BYTES_PER_FIELD_ELEMENT = 4096 * 32 = 131072` bytes (`DATA`) representing a SSZ-encoded `Blob` as defined in [EIP-4844](https://eips.ethereum.org/EIPS/eip-4844).

It does however not look like we SSZ-encode the blob? I think this is mandatory here? (per spec)

[g11tech]

The spec says:

The fields are encoded as follows:

- `blob`: `DATA` - `FIELD_ELEMENTS_PER_BLOB * BYTES_PER_FIELD_ELEMENT = 4096 * 32 = 131072` bytes (`DATA`) representing a SSZ-encoded `Blob` as defined in [EIP-4844](https://eips.ethereum.org/EIPS/eip-4844).

It does however not look like we SSZ-encode the blob? I think this is mandatory here? (per spec)

this the blobs generated/provided in tx are already in ssz encoded format which is just 131072 bytes, we don't have to do anything here

[g11tech]

The spec says:

The fields are encoded as follows:

- `blob`: `DATA` - `FIELD_ELEMENTS_PER_BLOB * BYTES_PER_FIELD_ELEMENT = 4096 * 32 = 131072` bytes (`DATA`) representing a SSZ-encoded `Blob` as defined in [EIP-4844](https://eips.ethereum.org/EIPS/eip-4844).

It does however not look like we SSZ-encode the blob? I think this is mandatory here? (per spec)

this the blobs generated/provided in tx are already in ssz encoded format which is just 131072 bytes, we don't have to do anything here

[jochem-brouwer]

Ok, I was not aware that the blobs were already SSZ-encoded (do not see this in EIP-4844), but if that's the case that's great, otherwise we implicitly have to take in the SSZ dependency (which we will have to do at some point when we switch to SSZ from RLP in general)

[jochem-brouwer]

LGTM!