case_when with is_null -> fill_null

[onursatici]

Summary

zip kernels are generally slower than fill_null kernels, and CASE WHEN is_null(x) THEN c ELSE x END needs to resolve x twice, whereas fill_null(x, c) does resolve x once

[codspeed-hq]

Merging this PR will improve performance by 30.19%

⚠️ Unknown Walltime execution environment detected

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⚡ 3 improved benchmarks
✅ 1504 untouched benchmarks

Performance Changes

	Mode	Benchmark	BASE	HEAD	Efficiency
⚡	Simulation	chunked_bool_canonical_into[(1000, 10)]	45.3 µs	30.3 µs	+49.41%
⚡	Simulation	chunked_varbinview_canonical_into[(1000, 10)]	197.1 µs	160.8 µs	+22.53%
⚡	Simulation	chunked_varbinview_into_canonical[(1000, 10)]	211.7 µs	175.6 µs	+20.54%

Tip

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_{Comparing os/case-when-fill-null-rule (f5f4749) with develop (4e6e9ed)}