Rename get_sliced_child to sliced_child.

[bdice]

This PR renames the lists/structs methods get_sliced_child to sliced_child. This resolves some inconsistent naming (like structs_column_device_view::sliced_child). Resolves #10666.

[codecov]

Codecov Report

Merging #10881 (bbae90a) into branch-22.06 (6352b4e) will increase coverage by 0.03%.
The diff coverage is 100.00%.

@@               Coverage Diff                @@
##           branch-22.06   #10881      +/-   ##
================================================
+ Coverage         86.29%   86.33%   +0.03%     
================================================
  Files               144      144              
  Lines             22656    22665       +9     
================================================
+ Hits              19552    19567      +15     
+ Misses             3104     3098       -6     

Impacted Files	Coverage Δ
python/dask_cudf/dask_cudf/groupby.py	97.42% <100.00%> (+<0.01%)	⬆️
python/dask_cudf/dask_cudf/tests/test_groupby.py	100.00% <100.00%> (ø)
python/cudf/cudf/core/dataframe.py	93.78% <0.00%> (+0.04%)	⬆️
python/cudf/cudf/core/column/string.py	88.78% <0.00%> (+0.12%)	⬆️
python/cudf/cudf/core/groupby/groupby.py	91.79% <0.00%> (+0.22%)	⬆️
python/cudf/cudf/core/tools/datetimes.py	84.49% <0.00%> (+0.30%)	⬆️
python/cudf/cudf/core/column/lists.py	91.70% <0.00%> (+0.97%)	⬆️

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[davidwendt]

So I'm not a big fan of this. I do think the get_ prefix is unnecessary for simple accessors or for retrieving virtual attributes of a class. But I prefer a verb prefix if the method must manufacture the result as in this case. The sliced child is not really an attribute of the class and so must be created on every call.
I mentioned virtual attribute because I know we have cases like null_count() which internally may require it to calculate the answer. But I think it is a reasonable expectation that it appear as a simple accessor. This is still not the case of a sliced child which I think does not meet this criteria as an expected attribute of the view.
If get is too controversial then perhaps make_sliced_child() or something similar.

[bdice]

@davidwendt I appreciate the critique -- my primary goal here is consistency with structs_column_device_view::sliced_child. I have heard we try to avoid get_ prefixes where possible, which led to this changeset, but I agree with your reasoning that this may be a different case than an accessor. Do you think it would be better to rename structs_column_device_view::sliced_child to structs_column_device_view::get_sliced_child?

[davidwendt]

... I have heard we try to avoid get_ prefixes where possible, which led to this changeset, but I agree with your reasoning that this may be a different case than an accessor. Do you think it would be better to rename structs_column_device_view::sliced_child to structs_column_device_view::get_sliced_child?

Yes, I do.

[bdice]

Closing this in favor of #10885.