fix doxygen warnings

[karthikeyann]

This PR fixes 433 doxygen warnings.

As prerequisite for doxygen CI check #9373, the warnings from doxygen should be minimized as much as possible.
This is one of the series of PRs to fix doxygen documentation warnings.

[ajschmidt8]

Please make sure to open PRs from forks in the future. Not the source repository.

[codecov]

Codecov Report

Merging #10842 (08ed165) into branch-22.06 (e0d94f3) will increase coverage by 0.03%.
The diff coverage is 100.00%.

❗ Current head 08ed165 differs from pull request most recent head 64b1dcf. Consider uploading reports for the commit 64b1dcf to get more accurate results

@@               Coverage Diff                @@
##           branch-22.06   #10842      +/-   ##
================================================
+ Coverage         86.28%   86.32%   +0.03%     
================================================
  Files               144      144              
  Lines             22654    22656       +2     
================================================
+ Hits              19548    19557       +9     
+ Misses             3106     3099       -7     

Impacted Files	Coverage Δ
python/cudf/cudf/core/resample.py	88.97% <ø> (ø)
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/dask_cudf/dask_cudf/core.py	73.62% <0.00%> (+0.26%)	⬆️
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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[karthikeyann]

@gpucibot merge