Refactor: replace contains_file_named with index_for_name #558

Job	Run time
fuzz_read	3h 23m 27s
Build and test: ubuntu-latest, stable	40s
Checking fmt and docs	23s
clippy	25s
Build and test: ubuntu-latest, nightly	45s
fuzz_read_with_no_features	2h 39m 33s
Build and test: ubuntu-latest, msrv	50s
fuzz_write	3h 35m 20s
Build and test: macOS-latest, stable	1m 18s
Build and test: macOS-latest, nightly	4m 0s
fuzz_write_with_no_features	28m 10s
Build and test: macOS-latest, msrv	4m 54s
Build and test: windows-latest, stable	2m 39s
Build and test: windows-latest, nightly	2m 11s
Build and test: windows-latest, msrv	1m 43s
	10h 26m 18s

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