Blob codec agnostic test vectors

[Inphi]

The test vector assumes the data input are encoded as blobs using this encoder. But there are multiple ways of encoding blobs (ex: tightly packing byte values that are much less than the field element size).

To allow for greater compatibility across client implementations, the test vector should have the encoded data blob as input (i.e. a 128 KiB hex encoded string).

cc: @abdelhamidbakhta