[Storm SQL] Change underlying API to Streams API (for 2.0.0)

Since we dropped features which conform to the Trident semantic, Storm SQL doesn't need to rely on Trident, which is micro-batch.

Both core API and Streams API are candidates, but we should implement some bolts when we decide to rely on core API, whereas we don't need to do that for Streams API. (If we need to, that's the point to improve Streams API.)

Streams API also provides windowing feature via tuple-to-tuple semantic, so it's ready for STORM-2405 too.