This PR extends the infer_gen_constraints function to the options arg of a QAIngredient.

This minimizes verbosity in the common pattern where we have a {column} = {QAIngredient} predicate, and enforces a choice amongst the column values (unless otherwise specified).

Now, when we run blend with infer_gen_constraints=True, the below queries are equivalent.

SELECT * FROM w
    WHERE name = {{
        LLMQA(
            'Choose a name'
        )
    }}

SELECT * FROM w
    WHERE name = {{
        LLMQA(
            'Choose a name',
            options='w::name'
        )
    }}

Benchmark Runtimes

The benchmarks saw no noticeable change in performance with this PR. A little uptick in the 'rugby' task, will keep an eye on that in the future.

Before:

After: