[REVIEW] Fix usecols parameter handling in dask_cudf.read_csv

[galipremsagar]

Fixes: #9387

This PR fixes usecols parameter usage in dask_cudf.read_csv. When the csv read using byterange's the csv reader has to be passed complete column names in names param but should pass usecols to return the exact columns that are needed only.

[codecov]

Codecov Report

Merging #9618 (8f18e72) into branch-21.12 (ab4bfaa) will decrease coverage by 0.09%.
The diff coverage is n/a.

❗ Current head 8f18e72 differs from pull request most recent head 18a9b3e. Consider uploading reports for the commit 18a9b3e to get more accurate results

@@               Coverage Diff                @@
##           branch-21.12    #9618      +/-   ##
================================================
- Coverage         10.79%   10.69%   -0.10%     
================================================
  Files               116      117       +1     
  Lines             18869    19353     +484     
================================================
+ Hits               2036     2070      +34     
- Misses            16833    17283     +450     

Impacted Files	Coverage Δ
python/dask_cudf/dask_cudf/sorting.py	92.90% <0.00%> (-1.21%)	⬇️
python/cudf/cudf/io/csv.py	0.00% <0.00%> (ø)
python/cudf/cudf/io/orc.py	0.00% <0.00%> (ø)
python/cudf/cudf/__init__.py	0.00% <0.00%> (ø)
python/cudf/cudf/core/frame.py	0.00% <0.00%> (ø)
python/cudf/cudf/core/index.py	0.00% <0.00%> (ø)
python/cudf/cudf/io/parquet.py	0.00% <0.00%> (ø)
python/cudf/cudf/core/series.py	0.00% <0.00%> (ø)
python/cudf/cudf/core/reshape.py	0.00% <0.00%> (ø)
python/cudf/cudf/utils/dtypes.py	0.00% <0.00%> (ø)
... and 44 more

---

Continue to review full report at Codecov.

Legend - Click here to learn more
Δ = absolute <relative> (impact), ø = not affected, ? = missing data
Powered by Codecov. Last update 9fa6ec0...18a9b3e. Read the comment docs.

[galipremsagar]

rerun tests

[galipremsagar]

@gpucibot merge