Refactor file handling and dataset file listing logic #3

Job	Run time
plan	27s
build-local-artifacts (x86_64-apple-darwin)	5m 1s
build-local-artifacts (aarch64-unknown-linux-gnu)	2m 35s
build-local-artifacts (x86_64-unknown-linux-gnu)	3m 19s
build-local-artifacts (aarch64-apple-darwin)	4m 43s
build-local-artifacts (x86_64-pc-windows-msvc)	6m 29s
	22m 34s

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