sha2

[WIP] blake2: integrate `blake2b_simd`/`blake2s_simd` crates #1536

Job	Run time
riscv64-zknh	46s
riscv32-zknh	19s
minimal-versions / minimal-versions	36s
set-msrv / set-msrv	1s
build	1s
linux	1s
macos	1s
cross	1s
wasm	1s
windows	1s
	1m 48s

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