Small

feat: `associative_vector` rework #131

Job	Run time
Windows-MSVC/2019/Static/X86/Release	2m 52s
Windows-MSVC/2019/Static/X64/Release	3m 3s
Ubuntu/20.04/Static/X64/Release	1m 21s
Ubuntu/22.04/Static/X64/fsanitize	1m 18s
MacOSX/12/Static/X64/Release	1m 25s
	9m 59s

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