Improve `AggregateFuzz` testing: generate random queries

[alamb]

Which issue does this PR close?

Part of https://github.com/apache/datafusion/issues/12114

Rationale for this change

Now that we have a great aggregation fuzz testing framework from @Rachelint , lets use it to increase coverage

Specifically while thinking about how to improve test coverage I think the key constraints are what types are supported by what aggregate functions. Thus it makes sense to have different functions tested in different combinations

What changes are included in this PR?

1. Add a query generator to randomly create queries
2. Update aggregate fuzz testing to cover various permutations of types and aggregates
3. List other potential things to test

Are these changes tested?

Only tests

Are there any user-facing changes?

No, only tests

[alamb]

FYI @Rachelint

[Rachelint]

The query generator seems really excellent!

[alamb]

Thank you @goldmedal

[goldmedal]

Thanks @alamb and @Rachelint for reviewing!