LA-1696 Fix conversions for C_Verify
LA-1696 Fix conversions for C_Verify

Problem:
   Uses to_char_array, which can cause confusion with
conversions.

Solution:
  Use to_byte_array w/ from_bytestring to explicitly state
what data types we are expecting

Change-Id: Ifb75f9f83b0f1217cfaa63ad092dbef45adbf995

gemalto/pycryptoki