Extend path search struct to work as request builder.

[CathalMullan]

For some reason - this results in 2.5% slower benchmarks locally.

Want to at least understand why before merging.

UPDATE: With the new benchmark env, this is no slower than before. Good!

[codecov]

Codecov Report

Attention: Patch coverage is 84.74576% with 9 lines in your changes missing coverage. Please review.

✅ All tests successful. No failed tests found.

Files with missing lines	Patch %	Lines
README.md	66.66%	0 Missing and 4 partials ⚠️
src/request.rs	73.33%	3 Missing and 1 partial ⚠️
src/errors/request.rs	95.83%	1 Missing ⚠️

Files with missing lines	Coverage Δ
src/errors/routable.rs	95.83% <ø> (ø)
src/router.rs	93.96% <100.00%> (+0.09%)	⬆️
src/errors/request.rs	95.83% <95.83%> (ø)
README.md	67.79% <66.66%> (+5.05%)	⬆️
src/request.rs	73.33% <73.33%> (ø)

[codspeed-hq]

CodSpeed Performance Report

Merging #212 will not alter performance

_{Comparing builder (ac7d638) with main (ae95bdf)}

Summary

✅ 19 untouched benchmarks