perf: strict lifecycle and reduce allocation

[SyMind]

Mark the lifetimes of OnSource, OnChunk, and OnName, indicating that the lifetime of the &str type parameters in their methods is consistent with StreamSource. This ensures that all intermediate steps for computing the source map can directly hold &str without worrying about it being dropped, thereby reducing memory overhead.

[codspeed-hq]

CodSpeed Performance Report

Merging #106 will improve performances by 24.08%

_{Comparing SyMind:perf-by-on-index (6d7bb00) with main (5f8b4a0)}

Summary

⚡ 3 improvements
✅ 2 untouched benchmarks

Benchmarks breakdown

	Benchmark	main	SyMind:perf-by-on-index	Change
⚡	concat_generate_base64	61.4 µs	56.6 µs	+8.39%
⚡	concat_generate_string	59 µs	54.4 µs	+8.43%
⚡	replace_large_minified_source	126.5 ms	101.9 ms	+24.08%