perf(idastar)!: use set for nodes encountered in path

[samueltardieu]

This is a breaking change as it requires the node type to implement Hash

[codspeed-hq]

CodSpeed Performance Report

Merging #633 will degrade performances by 30.58%

_{Comparing push-kkyqttxvmuol (8493c73) with main (a4ac532)}

Summary

⚡ 2 improvements
❌ 1 regressions
✅ 33 untouched benchmarks

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

Benchmarks breakdown

	Benchmark	main	push-kkyqttxvmuol	Change
❌	fill-corner_to_corner_idastar	152.9 µs	220.3 µs	-30.58%
⚡	fill-no_path_astar	1.5 ms	1.2 ms	+32.15%
⚡	fill-no_path_dijkstra	1.5 ms	1.1 ms	+28.91%