Move Sinsemilla primitive impl into `sinsemilla` crate #4052

Job	Run time
Build target wasm32-unknown-unknown	14s
Build target wasm32-wasi	15s
Test on ubuntu-latest	13s
Test on windows-latest	11s
Test on i686-unknown-linux-gnu	20s
Test on macOS-latest	1s
Bitrot check	14s
Test on i686-unknown-linux-gnu with beta features	26s
Book tests	16s
Test on ubuntu-latest with beta features	12s
Test on i686-unknown-linux-gnu with nightly features	23s
Test on windows-latest with beta features	9s
Code coverage	2m 25s
Test on macOS-latest with beta features	14s
Test on ubuntu-latest with nightly features	12s
Test on windows-latest with nightly features	11s
Test on macOS-latest with nightly features	14s
Intra-doc links	15s
Rustfmt	15s
	6m 40s

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