BUG: Fix `pd.read_csv` with encoding parameter

[aresnow1]

What do these changes do?

Fix pd.read_csv with encoding parameter.

Related issue number

Fixes #613

Check code requirements

• [x] tests added / passed (if needed)
• [x] Ensure all linting tests pass

[codecov[bot]]

Codecov Report

Merging #614 (3d5d9bb) into main (d4092fa) will decrease coverage by 18.99%. The diff coverage is 100.00%.

@@             Coverage Diff             @@
##             main     #614       +/-   ##
===========================================
- Coverage   93.53%   74.55%   -18.99%     
===========================================
  Files        1012     1012               
  Lines       78737    78738        +1     
  Branches    16358    16358               
===========================================
- Hits        73647    58703    -14944     
- Misses       3427    17579    +14152     
- Partials     1663     2456      +793     

Flag	Coverage Δ
unittests	74.43% <100.00%> (-19.01%)	:arrow_down:

Flags with carried forward coverage won't be shown. Click here to find out more.

Impacted Files	Coverage Δ
...hon/xorbits/_mars/dataframe/datasource/read_csv.py	60.51% <100.00%> (-26.13%)	:arrow_down:

... and 472 files with indirect coverage changes