Add hints to bucket analyzer / INFER

For INFER or the bucket analyzer, users should be able to pass hints to help schema inference. For example, a user may know that the "type" attribute in the JSON determines what type a JSON object is, or perhaps the ID or a section of the ID serves the same purpose.

In the case of the travel-sample data, there are objects of type "hotel" and objects of type "landmark" that are currently too similar to be detected as two different classes with the default bucket analyzer settings.