encodings/fsst: add OptimizedDecompressor for throughput #7485

Performance Gate Passed

⚡ 9 improved benchmarks
✅ 1154 untouched benchmarks
⏩ 1457 skipped benchmarks¹

	Mode	Benchmark	`BASE`	`HEAD`	Efficiency
⚡	Simulation	`take_map[(0.1, 0.5)]`	1,154.5 µs	990.4 µs	+16.57%
⚡	Simulation	`take_map[(0.1, 1.0)]`	2 ms	1.7 ms	+19.08%
⚡	Simulation	`patched_take_10k_contiguous_not_patches`	258.4 µs	228.1 µs	+13.29%
⚡	Simulation	`patched_take_10k_first_chunk_only`	302 µs	271.8 µs	+11.14%
⚡	Simulation	`patched_take_10k_dispersed`	316 µs	285.8 µs	+10.58%
⚡	Simulation	`patched_take_10k_random`	270.3 µs	240 µs	+12.64%
⚡	Simulation	`patched_take_10k_contiguous_patches`	258.1 µs	227.7 µs	+13.32%
⚡	Simulation	`take_10k_first_chunk_only`	270.6 µs	225.7 µs	+19.89%
⚡	Simulation	`take_10k_dispersed`	284.4 µs	239.5 µs	+18.76%

_{Comparing ji/fsst-optimized-decompressor (c1f032a) with develop (12f63a4)}

1457 benchmarks were skipped, so the baseline results were used instead. If they were deleted from the codebase, click here and archive them to remove them from the performance reports. ↩