Groupby hash aggregations use sort-based implementation if nested-type columns are used as values

We should be able to use nested-type columns as values and still be able to invoke a hash-based groupby, as hash-based is generally faster so we do not want to be silently using sort-based. https://github.com/rapidsai/cudf/blob/abc0d41d1d9033d581948ae19384e0aa0f33da77/cpp/src/groupby/hash/groupby.cu#L654-L656

Reference thread: https://github.com/rapidsai/cudf/pull/13795#discussion_r1373454172