Add filter to get_column_values

[epapineau]

Describe the feature

Add an optional argument to the get_column_values macro that allows a where clause to be passed to the generated SQL.

Describe alternatives you've considered

The alternative is using run_query to get these values, but the docs state:

Here's an example of using this (though if you're using run_query to return the values of a column, check out the get_column_values macro in the dbt-utils package).

Additional context

No additional context comes to mind

Who will this benefit?

ME :) But also anyone trying to get a narrow list for cross-filtering models without a join.

Are you interested in contributing this feature?

Heck yea 😎