support checking for object modified during download #215

Job	Run time
fmt	9s
clippy	1m 22s
minrust	48s
docs	49s
basic checks	1s
check deps with cargo-deny	14s
features	1m 2s
saniters	3m 9s
check-external-types (ubuntu-24.04)	53s
Test S3 transfer manager HLL (ubuntu-24.04)	2m 12s
Test S3 transfer manager HLL (windows-2022)	4m 41s
Test S3 transfer manager HLL (macos-14)	3m 37s
Required checks pass	1s
	18m 58s

Provide feedback