crypto: testmgr - add test vectors for blake2b

Test vectors for blake2b with various digest sizes. As the algorithm is
the same up to the digest calculation, the key and input data length is
distributed in a way that tests all combinanions of the two over the
digest sizes.

Based on the suggestion from Eric, the following input sizes are tested
[0, 1, 7, 15, 64, 247, 256], where blake2b blocksize is 128, so the
padded and the non-padded input buffers are tested.

          blake2b-160  blake2b-256  blake2b-384  blake2b-512
         ---------------------------------------------------
len=0   | klen=0       klen=1       klen=32      klen=64
len=1   | klen=32      klen=64      klen=0       klen=1
len=7   | klen=64      klen=0       klen=1       klen=32
len=15  | klen=1       klen=32      klen=64      klen=0
len=64  | klen=0       klen=1       klen=32      klen=64
len=247 | klen=32      klen=64      klen=0       klen=1
len=256 | klen=64      klen=0       klen=1       klen=32

Where key:

- klen=0: empty key
-...