Refactor `additional_select_columns` dbt test params to support more configurable naming and aggregation

[jeancochrane]

Most of our generic dbt test functions support an additional_select_columns parameter that instructs the test to select additional columns from the base table for use in test failure reporting. There are a few problems with the current implementation, however:

• Each test generic implements additional_select_columns separately
• The expression_is_true test uses the older name select_columns for the same parameter
• unique_combination_of_columns and res_class_matches_pardat both permit an object structure for aliasing and aggregation, but this structure is not supported in other generics, and the two generics that do support it implement it differently

This PR represents an attempt to resolve these issues and standardize our implementation of additional_select_columns attributes using a new macro format_additional_select_columns.

Closes https://github.com/ccao-data/data-architecture/issues/330.

[jeancochrane]

~Oops, I marked this PR as ready for review before running the final check (generating the output workbook and making sure it still looks correct). Doing that now; no need to review just yet.~ Done, ready for review!