Adds a fast path for ExecutionPayloadEnvelope and BlobAndProofListV*
that bypasses encoding/json's reflection and re-validation, which are
expensive for large payloads with many blobs. Also hand-rolls the
jsonrpcMessage wire encoding in the RPC codec to avoid a second
re-validation pass when writing responses to the connection.
Resolves#33814
---------
Co-authored-by: Marius van der Wijden <m.vanderwijden@live.de>
Co-authored-by: Felix Lange <fjl@twurst.com>
