A respondent's uploaded file, inline

The file's bytes in the JSON body under the same API key: UTF-8 text for text types, base64 otherwise. For a caller that cannot fetch `download_url`. Files over 4 MB answer 413; use `download_url` for those.

curl -X GET "https://example.com/v1/files/string/content"

{  "id": "string",  "object": "file_content",  "filename": "string",  "mime": "string",  "size_bytes": 0,  "encoding": "utf8",  "data": "string"}