Result class not generalised for all Evaluation Functions

[neagualexa]

The Result class that contains the output of the evaluation function has specific attributes (such as latex and simplified) that are not necessarily used by many evaluation functions.

It would be useful to have a Result class that allows for other specific attributes to be added onto it, besides the necessary Feedback & Is_correct.

For instance for the shortTextAnswer evaluation function, I would want to also save the attributes: processing_time (float), metadata(dict), evaluation_type(str). However I could also save all of those under the metadata dictionary as well.

[neagualexa]

Same request for the Params struct