initialize fuzzing harness

[R9295]

[alonbl]

Hello @R9295,

I would like to avoid running binary infra due to security reasons.

I pushed a fix into [https://github.com/OpenSC/pkcs11-helper/pull/74] including unittest.

If you find anything, I will appreciate to receive a test vector as file, so I can improve the implementation.

Thank you so much! Alon