fix: dbt as_bool and as_number filters should return their original input values

[newtonapple]

This matches dbt's TEXT_FILTERS implementation.

[erindru]

On the dbt side, does the Jinja environment usually get constructed with native=False?

I notice there is a different codepath that decides if NATIVE_FILTERS or TEXT_FILTERS is used, and NATIVE_FILTERS implements as_bool / as_number slightly differently