refactor(python): Refactor parsing of data type inputs to Polars data types

[stinodego]

Ref #13117

Refactoring the logic that parses dtype inputs to a Polars data type, for example in the Series constructor.

This is towards improving the logic and consistently applying it across the API.

[codecov]

Codecov Report

Attention: Patch coverage is 96.58120% with 4 lines in your changes missing coverage. Please review.

Project coverage is 80.83%. Comparing base (0a04ad1) to head (cb953d9).
Report is 1 commits behind head on main.

Files	Patch %	Lines
py-polars/polars/_utils/construction/series.py	50.00%	2 Missing ⚠️
py-polars/polars/io/csv/batched_reader.py	50.00%	1 Missing ⚠️
py-polars/polars/io/database/_inference.py	50.00%	1 Missing ⚠️

Additional details and impacted files

@@            Coverage Diff             @@
##             main   #17164      +/-   ##
==========================================
+ Coverage   80.79%   80.83%   +0.04%     
==========================================
  Files        1464     1465       +1     
  Lines      191961   192038      +77     
  Branches     2743     2740       -3     
==========================================
+ Hits       155100   155240     +140     
+ Misses      36350    36293      -57     
+ Partials      511      505       -6     

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