decodeChunk
Decode the header fields and payload slice from a raw received chunk. Returns null if bytes is shorter than HEADER_SIZE or the header is internally inconsistent (e.g. chunkIndex ≥ chunkCount, chunkCount = 0).
Decode the header fields and payload slice from a raw received chunk. Returns null if bytes is shorter than HEADER_SIZE or the header is internally inconsistent (e.g. chunkIndex ≥ chunkCount, chunkCount = 0).