Enhance the console sink to provide watermark and state information

As discussed in the dev mailing list, we should enhance the console sink for Structured Streaming to additionally provide information about:

• The stream's watermark at the end of the batch
• The rows in state at the end of each batch

This will be enabled via an `option` on the sink. Since both of these additions are for stateful queries only, the option will not affect stateless queries. To make parsing the output easier, timestamps will be duration-rendered (i.e. "1 second" instead of the ISO 8601 extened timestamp). For joins, just the KeyWithIndexToValue will be shown. If there are multiple stateful operators, we'll print a state table for each.

These considerations are up to discussion either in this thread or in the PR.