[BUG] Dask-cuDF sort_values ignores unsupported kwargs silently

[rjzamora]

Describe the bug
The sort_values implementation in Dask-cuDF produces correct results, but does not raise an error or warning when unsupprted kwargs are supplied. A critical example is inplace.

Steps/Code to reproduce bug

import cudf, dask_cudf

df = dask_cudf.from_cudf(cudf.DataFrame({"a": [0, 1]*3}), npartitions=2)
df.sort_values("a", inplace=True)
df.compute()

Produces unsorted result:

   a
0  0
1  1
2  0
3  1
4  0
5  1

This is not because sort_values does not sort the DataFrame, but because the result is not stored "in place".

Expected behavior
I would expect dask_cudf to raise an error when an unsupported argument (like inplace) is used.

Additional context
Thanks to @bschifferer for bringing this problem to my attention.