[CHORE] Move all python wrapping logic to separate module

[raunakab]

Overview

Inside of daft-functions the python wrapping logic was all interspersed alongside the actual implementations. This made the implementations hard to parse through.

This PR moves all the python-wrapping out of the implementation tree and into a new module tree (named python).

Note that this is how our other crates (e.g., daft-dsl) do python API wrapping.

[codspeed-hq]

CodSpeed Performance Report

Merging #3458 will degrade performances by 55.02%

_{Comparing chore/daft-functions-cleanup (5c3969e) with main (465510f)}

Summary

❌ 1 regressions
✅ 16 untouched benchmarks

⚠️ Please fix the performance issues or acknowledge them on CodSpeed.

Benchmarks breakdown

	Benchmark	main	chore/daft-functions-cleanup	Change
❌	test_iter_rows_first_row[100 Small Files]	165.8 ms	368.6 ms	-55.02%

[codecov]

Codecov Report

Attention: Patch coverage is 93.91892% with 18 lines in your changes missing coverage. Please review.

Project coverage is 77.43%. Comparing base (465510f) to head (5c3969e).
Report is 1 commits behind head on main.

Files with missing lines	Patch %	Lines
src/daft-functions/src/python/image.rs	80.64%	6 Missing ⚠️
src/daft-functions/src/python/misc.rs	84.61%	6 Missing ⚠️
src/daft-functions/src/python/uri.rs	86.66%	6 Missing ⚠️

Additional details and impacted files

@@            Coverage Diff             @@
##             main    #3458      +/-   ##
==========================================
- Coverage   77.53%   77.43%   -0.10%     
==========================================
  Files         690      695       +5     
  Lines       84703    84347     -356     
==========================================
- Hits        65672    65317     -355     
+ Misses      19031    19030       -1     

Files with missing lines	Coverage Δ
src/daft-functions/src/count_matches.rs	63.04% <ø> (-7.14%)	⬇️
src/daft-functions/src/distance/cosine.rs	57.98% <ø> (-1.37%)	⬇️
src/daft-functions/src/float/fill_nan.rs	58.82% <ø> (-4.34%)	⬇️
src/daft-functions/src/float/is_inf.rs	57.57% <ø> (-4.59%)	⬇️
src/daft-functions/src/float/is_nan.rs	63.63% <ø> (-3.94%)	⬇️
src/daft-functions/src/float/not_nan.rs	57.57% <ø> (-4.59%)	⬇️
src/daft-functions/src/hash.rs	76.47% <ø> (-1.72%)	⬇️
src/daft-functions/src/image/crop.rs	47.16% <ø> (-3.71%)	⬇️
src/daft-functions/src/image/decode.rs	51.21% <ø> (-11.75%)	⬇️
src/daft-functions/src/image/encode.rs	57.57% <ø> (-5.59%)	⬇️
... and 70 more

... and 1 file with indirect coverage changes