Add Blake2b and Blake2s hash support for crypto backend.
We support most recent crypto algorithms, so this is only addition of the Blake hash family.
Kernel and gcrypt crypto backend supports all variants, OpenSSL only Blake2b-512 and Blake2s-256.
There is no useable support for NSS and Nettle yet.
Crypto backend supports kernel notation e.g. "blake2b-512" that is translated to the library backend names.