Regenerate tests that describe the test content instead of creating concrete instance

[bzorn]

When an input in a particular form is expected, like a document describing something, the test generator will generate a description of what the document should contain instead of generating a concrete example of such a document.

A solution would be to run the validate script and if it rejects with the reason that it isn't what the spec expects, to regenerate.

[pelikhan]

We should use an extra LLM call to expand these test case skeletons. It can be a flag on the tool or maybe automatically.

[bzorn]

This was fixed with the testExpansions and testGenerations parameters.