feat(python)!: Update reshape to return Array types instead of List types

[stinodego]

Closes #14005

reshape now returns an Array type instead of a List type.

Users can restore the old functionality by calling .arr.to_list() on the output. Note that this is not more expensive than it would be to create a List type directly, because reshaping into an array is basically free.

Example

Before:

>>> s = pl.Series([1, 2, 3, 4, 5, 6])
>>> s.reshape((2, 3))
shape: (2,)
Series: '' [list[i64]]
[
        [1, 2, 3]
        [4, 5, 6]
]

After:

>>> s.reshape((2, 3))
shape: (2,)
Series: '' [array[i64, 3]]
[
        [1, 2, 3]
        [4, 5, 6]
]

[codspeed-hq]

CodSpeed Performance Report

Merging #16825 will not alter performance

_{Comparing reshape-array (d4e7df0) with main (92af769)}

Summary

✅ 37 untouched benchmarks

[codecov]

Codecov Report

Attention: Patch coverage is 92.30769% with 4 lines in your changes missing coverage. Please review.

Project coverage is 81.38%. Comparing base (0f1eb18) to head (d4e7df0).
Report is 2 commits behind head on main.

Files	Patch %	Lines
crates/polars-core/src/series/ops/reshape.rs	90.00%	4 Missing ⚠️

Additional details and impacted files

@@            Coverage Diff             @@
##             main   #16825      +/-   ##
==========================================
- Coverage   81.40%   81.38%   -0.03%     
==========================================
  Files        1425     1425              
  Lines      187627   187638      +11     
  Branches     2702     2702              
==========================================
- Hits       152738   152701      -37     
- Misses      34393    34441      +48     
  Partials      496      496              

☔ View full report in Codecov by Sentry.
📢 Have feedback on the report? Share it here.