ChunkReqPayloadMappings: ChunkReqPayloadMapping[]

Specify all of the mappings between columns or fields in a CSV or JSONL file and keys in the ChunkReqPayload. Array fields like tag_set, image_urls, and group_tracking_ids can have multiple mappings. Boost phrase can also have multiple mappings which get concatenated. Other fields can only have one mapping and only the last mapping will be used.