message: changes for generate_context function
diff: @@ -178,9 +178,14 @@ impl AnoncredsService {
  }
  fn generate_context(accumulator_id: &str, user_id: &str) {
  - println!("{:?}, {:?}", accumulator_id, user_id);
  - let a = AnoncredsService::encode_attribute(accumulator_id, ByteOrder::Little);
  - println!("attr{}", a);
  + let accumulator_id_encoded = AnoncredsService::encode_attribute(accumulator_id, ByteOrder::Little);
  + let user_id_encoded = AnoncredsService::encode_attribute(user_id, ByteOrder::Little);
  + let a_e = BigNum::from_dec_str(&accumulator_id_encoded).unwrap();
  + let u_e = BigNum::from_dec_str(&user_id_encoded).unwrap();
  + let s = AnoncredsService::bitwise_or_big_int(&a_e, &u_e);
  + let mut result = hash(MessageDigest::sha256(), s.to_hex_str().unwrap().as_bytes()).unwrap();
  + let encoded_attribute = AnoncredsService::transform_byte_array_to_big_integer(&result);
  + println!("attr{:?}", encoded_attribute);
  }
  fn generate_vprimeprime() -> BigNum {
  let mut ctx = BigNumContext::new().unwrap();
  