ValueMappingEstimator in the Conversions catalog is missing the treatAsKeys parameter

[singlis]

When adding samples, I noticed that the treatValuesAsKeys parameter is not available as part of the Conversions catalog. Therefore I am not able to do this:

         var pipeline = ml.Transforms.Conversions.ValueMap(educationKeys, educationValues, true, ("EducationKeyType", "Education"));

And instead have to do this:

            var pipeline = new ValueMappingEstimator<string, string>(ml, educationKeys, educationValues, true, ("EducationKeyType", "Education"));

Therefore we should add another function to the Conversions Catalog to handle this.

[Ivanidzo4ka]

Is it still relevant? If yes, would you have time to fix it?

[singlis]

Note this was added by @artidoro, #2959