Implement belt-che

[makavity]

Hello, just implemented belt-che algorithm from STB 34.101.31-2020.
Benches:

running 4 tests
test decrypt_aad_only_16kb ... bench:      26,866.17 ns/iter (+/- 637.29) = 609 MB/s
test decrypt_msg_only_16kb ... bench:     142,738.17 ns/iter (+/- 2,617.87) = 114 MB/s
test encrypt_aad_only_16kb ... bench:      26,947.76 ns/iter (+/- 1,092.55) = 608 MB/s
test encrypt_msg_only_16kb ... bench:     156,133.59 ns/iter (+/- 8,565.73) = 104 MB/s

test result: ok. 0 passed; 0 failed; 0 ignored; 4 measured; 0 filtered out; finished in 13.68s

MacBook M3 Max.

@newpavlov