Add BlobAndProofV2

[Rjected]

Right now we have BlobAndProofV1:

alloy/crates/eips/src/eip4844/engine.rs

Lines 1 to 14 in 5ed9660

	//! Misc types related to the 4844
	use crate::eip4844::{Blob, Bytes48};
	use alloc::boxed::Box;
	/// Blob type returned in responses to `engine_getBlobsV1`: <https://github.com/ethereum/execution-apis/pull/559>
	#[derive(Debug, Clone, PartialEq, Eq)]
	#[cfg_attr(feature = "serde", derive(serde::Serialize, serde::Deserialize))]
	pub struct BlobAndProofV1 {
	/// The blob data.
	pub blob: Box<Blob>,
	/// The KZG proof for the blob.
	pub proof: Bytes48,
	}

A struct exactly like this should be added, called BlobAndProofV2, which contains the same fields as BlobAndProofV1 but with cell_proof instead of proof. The serde struct cfg will have to be adjusted to use camel case on all fields as well.

This link should be included in the docs as well:
ethereum/execution-apis#630

[varun-doshi]

I'd like to work on this