Refactor sql client's DynamicResult

Right now, the sql client Executor has different result handling logic for different result display mode. 

Different result is handled by child classes of `DynamicResult`. 

This leads to introducing page related API to the Executor, such as `snapshotResult`  and `retrieveResultPage`, which I think is inappropriate and will make things complicated. 

It will be benefit to simplify the responsibility of Executor about retrieving results to simply streaming back the SELECT result, and move the logic of dealing with different display mode into CliResultView.