Back implementations of SHA2, HMAC-SHA1, HMAC-SHA2 and HKDF-SHA2 by hacl-rs #1087

Job	Run time
extract	2m 40s
extract-header-only	2m 41s
diff	8s
build (macos-latest)	4m 28s
build (ubuntu-latest)	23m 17s
build (windows-latest)	3m 5s
diff-header-only	4s
build-header-only (macos-latest)	19s
build-header-only (ubuntu-latest)	23s
build-header-only (windows-latest)	1m 38s
	38m 43s

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