Add 'output_json_as_list' option to CLI (WIP)

[martynassateika]

Everything about this is still WIP, opening it up early in case I'm misunderstanding something.

By the way I needed to change this line on Windows to

opened = open(filename, "w")

to get the tests to pass:

https://github.com/stevearc/dql/blob/6b0ab8df07afd226816937ee98b4ef73187206fc/dql/engine.py#L581

Fixes https://github.com/stevearc/dql/issues/21.