Adds a file attachment to an existing referee

The attachment's Name field must be less than 255 characters.

The attachment's type will be automatically set depending on the Referee's type. ICE Contact referees do not support attachments.

The FileExtension must match the file contents and be a valid Windows extension, preceded by a full stop. Infinity will not be able to open the file if the extension doesn't match and it could cause issues within Infinity.

The attachment's Content must not exceed the max upload size configured in Infinity.

The max upload size can be retrieved from the /Reference/MaxUploadSize method (In KB)