Add test cases for generic tests config

[mikealfare]

resolves #

Problem

We are not testing that custom config values get pulled through for generic tests. We discovered that this is not actually happening. See https://github.com/dbt-labs/dbt-core/issues/10484.

Solution

Add tests that run generic tests with custom config and confirm that the config gets pulled through with the expected results. In this case, that means running using a different warehouse.

Checklist

• [x] I have read the contributing guide and understand what's expected of me
• [ ] I have run this code in development and it appears to resolve the stated issue
• [x] This PR includes tests, or tests are not required/relevant for this PR
• [x] This PR has no interface changes (e.g. macros, cli, logs, json artifacts, config files, adapter interface, etc) or this PR has already received feedback and approval from Product or DX

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