[Bug] Fix scenarios where --empty flag pushes limit 0 into metadata queries

[mikealfare]

resolves #213

Problem

We fixed dbt-snowflake when using --empty and running metadata queries.

Solution

Add the tests for that fix so other adapters can use it if necessary.

Implementation

1. Merge this PR demonstrating that these tests work
2. Move the bulk of this PR into dbt-tests-adapter (we`re here)
3. Create a final PR that removes most of this and uses the dbt-tests-adapter tests

Checklist

• 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
• This PR includes tests, or tests are not required/relevant for this PR
• 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

[github-actions]

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[colin-rogers-dbt]

Do we need to update this one too? https://github.com/dbt-labs/dbt-adapters/blob/bug/213-fix-empty-flag/dbt/include/global_project/macros/materializations/tests/where_subquery.sql#L9

[mikealfare]

Do we need to update this one too? https://github.com/dbt-labs/dbt-adapters/blob/bug/213-fix-empty-flag/dbt/include/global_project/macros/materializations/tests/where_subquery.sql#L9

I'm honestly not sure. Based on where this macro is, I assume it's used in the test materialization. However, I don't see where this macro is called. I looked in both dbt-adapters and dbt-snowflake and there's no reference outside of defining the macro. Either way, I think we'd want to limit the results here just like we would in other materializations. It also doesn't create invalid sql like it does in describe/show queries. I can add it if you feel otherwise, but I'm inclined to leave this as is.