Changes to Image Background Remover

added the non-success response with the status 500

removed the Not Found enum value from the message response property for the response status 404

removed the Unauthorized enum value from the message response property for the response status 401

added the required property code to the response with the 400 status

added the required property code to the response with the 401 status

added the required property code to the response with the 402 status

added the required property code to the response with the 404 status

added the required property code to the response with the 422 status

added the non-success response with the status 402

removed the required property frame_cost from the response with the 200 status