List a raw-data record's validation findings

List every validation finding recorded for this record.

Each finding reports the choices it supports in options, so a client renders the reviewer's buttons without a per-code table of its own.

The record's ingestion state — processing_status, reader, processed_at, processing_error — is on the record itself and comes back from GET /raw_data/{raw_data_id}; it is not duplicated here.