fix: Fix various Int128 operations

[lukemanley]

Fixes the following operations for Int128:

• abs
• cum_prod
• cum_sum
• interpolate
• product
• rolling_map
• eq
• ne
• ge
• gt
• le
• lt

[codecov]

Codecov Report

Attention: Patch coverage is 73.33333% with 4 lines in your changes missing coverage. Please review.

Project coverage is 79.05%. Comparing base (25fab78) to head (c768f30).
Report is 1 commits behind head on main.

Files with missing lines	Patch %	Lines
crates/polars-python/src/expr/rolling.rs	62.50%	3 Missing ⚠️
crates/polars-plan/src/dsl/mod.rs	0.00%	1 Missing ⚠️

Additional details and impacted files

@@            Coverage Diff             @@
##             main   #20515      +/-   ##
==========================================
+ Coverage   79.04%   79.05%   +0.01%     
==========================================
  Files        1563     1563              
  Lines      220798   220813      +15     
  Branches     2502     2502              
==========================================
+ Hits       174521   174572      +51     
+ Misses      45703    45667      -36     
  Partials      574      574              

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[codspeed-hq]

CodSpeed Performance Report

Merging #20515 will improve performances by 28.45%

_{Comparing lukemanley:fix-i128-ops (ed7043a) with main (25fab78)}

Summary

⚡ 1 improvements
✅ 40 untouched benchmarks

Benchmarks breakdown

	Benchmark	main	lukemanley:fix-i128-ops	Change
⚡	test_to_numpy_series_with_nulls	410.6 µs	319.6 µs	+28.45%

[ritchie46]

Awesome! Thanks a lot @lukemanley!