External use of sqllogictest machinery

[tshauck]

Is your feature request related to a problem or challenge?

I'd like to make the code that relates to DataFusion's sqllogictests implementation public so it can be used to test UDFs that are external to DataFusion's package.

Describe the solution you'd like

Per the discussion, I'll create a crate in this repo that makes various parts of the sqllogictest test framework. This will allow downstream users to import the code.

Describe alternatives you've considered

No response

Additional context

This issue is associated with this discussion: #7032. I'm opening this issue as the PR template requests an issue to associate with it for tracking purposes.