Add failing test for #3105

[jonmmease]

Which issue does this PR close?

Adds a failing test for #3105. I don't really understand the issue, and I don't currently plan to try to fix this myself, but I though it might by helpful to have the failing test for others to take a look at. If any of the maintainers are available to take a look, feel free to take over this branch.

[jonmmease]

Test failure on CI

 ---- exact_median stdout ----
thread 'exact_median' panicked at 'unexpected accumulator state in hash aggregate: Internal("AggregateState is not a scalar aggregate")', datafusion\core\src\physical_plan\aggregates\hash.rs:434:34
note: run with `RUST_BACKTRACE=1` environment variable to display a backtrace
thread 'exact_median' panicked at 'called `Result::unwrap()` on an `Err` value: ArrowError(ExternalError(Execution("Join Error: task 7 panicked")))', datafusion\core\tests\dataframe.rs:463:38

[alamb]

#3105 has been fixed and the fix included tests so I don't think this PR is needed anymore. Thanks again @jonmmease

[jonmmease]

Sure thing, thanks for fixing it!