Surface `jobs.query` and `jobs.getQueryResults` on the new v2 client

[alvarowolfx]

Since users can use those methods via centralizedClient.jobClient.query and centralizedClient.jobClient.getQueryResults, would make sense to just surface those.

Also samples can be updated to get rid of using jobClient directly.

Another debatable thing is, I think those clients can be made private, but is less of a problem imho.