DataFrame P2P Shuffling with stable ordering

[fjetter]

The P2P algorithm as is currently does not strictly guarantee ordering. This can be problematic for some order sensitive operations like groupby + first (dask/dask#10034) or for a drop_duplicates with keep (dask/dask#10708)

It's a little work but should be possible to get P2P to be stable

[hendrikmakait]

For the sake of documenting and being precise: When talking about stable ordering, the only thing we can guarantee with P2P is stable ordering between rows of the same shuffle key (i.e., the combination of values of the rows/index we shuffle on). With shuffling as a hashing-based operation, any ordering between keys is impossible.