[Unit Testing] Extend TestRedshiftUnitTestingTypes to include complex types

[MichelleArk]

Is this your first time submitting a feature request?

• I have read the expectations for open source contributors
• I have searched the existing issues, and I could not find an existing issue for this feature
• I am requesting a straightforward extension of existing dbt-spark functionality, rather than a Big Idea better suited to a discussion

Describe the feature

Per dbt-labs/dbt-core#8423 (comment), add redshift-specific input fixtures extend TestRedshiftUnitTestingTypes to test complex types (at least json & arrays / SUPER). Arrays have already been mocked out in the existing test.

Describe alternatives you've considered

n/a

Who will this benefit?

dbt users of dbt-redshift using unit testing

Are you interested in contributing this feature?

Anything else?

Depends on dbt-labs/dbt-adapters#113.

See dbt-bigquery for a similar example.