💾 add Python downsamplers + test identical as Rust impl

[jvdd]

This PR tackles the following

• add Python implementation of the downsamplers
  • tests the Rust downsamplers vs the Python implementation
• fixes bug for "without x" downsampling - Error with MinMax-aggregator when only setting y (and not x) #36

[codspeed-hq]

CodSpeed Performance Report

Merging #33 algo_testing_python (bd66a40) will not alter performances.

Summary

🔥 6 improvements
❌ 22 regressions
✅ 362 untouched benchmarks

🆕 0 new benchmarks
⁉️ 0 dropped benchmarks

Benchmarks breakdown

	Benchmark	main	algo_testing_python	Change
❌	test_minmax_no_x[True-float32-5,000-100,000]	2.8 ms	3.1 ms	-12.71%
🔥	test_minmax_with_x[True-float64-1,000-100,000]	8.1 ms	6.6 ms	18.30%
🔥	test_minmax_with_x[True-int32-1,000-100,000]	8.1 ms	6.8 ms	15.63%
❌	test_m4_no_x[True-float32-5,000-100,000]	1.8 ms	2 ms	-10.10%
❌	test_m4_no_x[True-float64-5,000-100,000]	2.2 ms	2.5 ms	-10.31%
🔥	test_m4_with_x[True-float32-1,000-100,000]	6.8 ms	5.7 ms	16.55%
🔥	test_m4_with_x[True-float64-1,000-100,000]	7.9 ms	6.2 ms	20.47%
❌	test_m4_with_x[True-float64-1,000-1,000,000]	13.4 ms	14.8 ms	-10.56%
❌	test_minmaxlttb_no_x[True-float32-5,000-1,000,000]	100.9 ms	111.7 ms	-10.65%
❌	test_minmaxlttb_no_x[True-float64-1,000-100,000]	19 ms	22.5 ms	-18.76%
❌	test_minmaxlttb_no_x[True-float64-1,000-1,000,000]	26.4 ms	29.9 ms	-13.37%
❌	test_minmaxlttb_no_x[True-float64-5,000-1,000,000]	99.6 ms	110.6 ms	-11.03%
❌	test_minmaxlttb_no_x[True-int32-100-100,000]	3.4 ms	3.8 ms	-11.72%
❌	test_minmaxlttb_no_x[True-int32-1,000-100,000]	12.5 ms	14.7 ms	-17.38%
❌	test_minmaxlttb_no_x[True-int32-5,000-1,000,000]	99.1 ms	109.8 ms	-10.84%
❌	test_minmaxlttb_no_x[True-int64-1,000-100,000]	18.8 ms	22.4 ms	-18.97%
❌	test_minmaxlttb_no_x[True-int64-1,000-1,000,000]	26.2 ms	29.7 ms	-13.38%
❌	test_minmaxlttb_no_x[True-int64-5,000-1,000,000]	95.9 ms	106.9 ms	-11.48%
❌	test_minmaxlttb_with_x[True-int32-100-100,000]	16.8 ms	21.3 ms	-26.67%
🔥	test_minmaxlttb_with_x[True-int32-1,000-100,000]	143.8 ms	122.9 ms	14.53%
🔥	test_minmaxlttb_with_x[True-int64-100-100,000]	38.4 ms	17.4 ms	54.79%
❌	test_minmaxlttb_with_x[True-int64-1,000-1,000,000]	146.9 ms	161.9 ms	-10.22%
❌	test_everynth[100-100,000]	95.3 µs	113.2 µs	-18.76%
❌	test_everynth[100-1,000,000]	95.4 µs	113.4 µs	-18.91%
❌	test_everynth[1,000-100,000]	110 µs	153.1 µs	-39.11%
❌	test_everynth[1,000-1,000,000]	111.4 µs	153.5 µs	-37.80%
❌	test_everynth[5,000-100,000]	164.3 µs	309 µs	-88.06%
❌	test_everynth[5,000-1,000,000]	164.1 µs	309.4 µs	-88.53%