feat: add AsyncBencher support

[art049]

Fixes #6

[codspeed-hq]

CodSpeed Performance Report

Merging #7 will degrade performances by 16.6%

_{⚠️ No base runs were found}

_{Falling back to comparing feat/support-async-bencher (79ecdb7) with main (9c6a5a8)}

Summary

❌ 4 regressions
✅ 37 untouched benchmarks

🆕 10 new benchmarks

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

Benchmarks breakdown

	Benchmark	main	feat/support-async-bencher	Change
❌	from_elem_decimal[2048]	4.2 µs	5 µs	-16.6%
❌	Auto	223.3 ns	251.1 ns	-11.06%
❌	Linear	223.3 ns	251.1 ns	-11.06%
❌	Flat	672.8 ns	756.1 ns	-11.02%
🆕	iter	N/A	29.4 ns	N/A
🆕	iter_with_setup	N/A	29.4 ns	N/A
🆕	iter_with_large_setup	N/A	29.4 ns	N/A
🆕	iter_with_large_drop	N/A	29.4 ns	N/A
🆕	iter_batched_small_input	N/A	29.4 ns	N/A
🆕	iter_batched_large_input	N/A	29.4 ns	N/A
🆕	iter_batched_per_iteration	N/A	29.4 ns	N/A
🆕	iter_batched_ref_small_input	N/A	29.4 ns	N/A
🆕	iter_batched_ref_large_input	N/A	29.4 ns	N/A
🆕	iter_batched_ref_per_iteration	N/A	29.4 ns	N/A