Support jinja expression statements

[drewbanin]

Feature

Feature description

http://jinja.pocoo.org/docs/2.10/extensions/#expression-statement

Presently, we hack expressions with:

{% set _ = my_dict.update({"a": 1, "b": 2}) %}

Instead, the jinja expression statement will make it possible to write:

{% do my_dict.update({"a": 1, "b": 2}) %}

This is a minor difference, but it will make jinja sql more readable and idiomatic.

Who will this benefit?

jinja writers