Revert "Adding structured evaluator (#339)"

This reverts commit 590d0d7.

Author: Akshay Rane

Cargo.lock

@@ -28,7 +28,6 @@ fn get_code(e: &Error) -> ErrorCode {
         Error::RetrievalError(_err) => 15,
         Error::MissingValue(_err) => 16,
         Error::FileNotFoundError(_) => 17,
-        Error::IllegalArguments(_) => 18,
     };
     ErrorCode::new(code)
 }