engine_getBlobsV2: Support partial responses

Reverts to previous behavior of supporting partial responses. This
enables optimizations that require these partial responses.

Author: MarcoPolo

src/engine/osaka.md

@@ -108,9 +108,7 @@ Consensus layer clients **MAY** use this method to fetch blobs from the executio
 Refer to the specification for [`engine_getBlobsV1`](./cancun.md#engine_getblobsv1) with changes of the following:
 
 1. Given an array of blob versioned hashes client software **MUST** respond with an array of `BlobAndProofV2` objects with matching versioned hashes, respecting the order of versioned hashes in the input array.
-2. Client software **MUST** return `null` in case of any missing or older version blobs. For instance, 
-   1. if the request is `[A_versioned_hash, B_versioned_hash, C_versioned_hash]` and client software has data for blobs `A` and `C`, but doesn't have data for `B`, the response **MUST** be `null`.
-   2. if the request is `[A_versioned_hash_for_blob_with_blob_proof]`, the response **MUST** be `null` as well.
+2. Client software **MUST** place responses in the order given in the request, using `null` for any missing blobs. For instance, if the request is `[A_versioned_hash, B_versioned_hash, C_versioned_hash]` and client software has data for blobs `A` and `C`, but doesn't have data for `B`, the response **MUST** be `[A, null, C]`.
 3. Client software **MUST** support request sizes of at least 128 blob versioned hashes. The client **MUST** return `-38004: Too large request` error if the number of requested blobs is too large.
 4. Client software **MUST** return `null` if syncing or otherwise unable to serve blob pool data.
 5. Callers **MUST** consider that execution layer clients may prune old blobs from their pool, and will respond with `null` if a blob has been pruned.