feat(serialzer): Add message format in send transfer

Allow send transfer in ASCII format message and set default to ascii.
Current message format are trytes and ascii, so we check only "trytes"
to differ than default.

serializer/serializer.c

@@ -243,6 +243,7 @@ status_t ta_send_transfer_req_deserialize(const char* const obj,
   cJSON* json_result = NULL;
   flex_trit_t tag_trits[NUM_TRITS_TAG], address_trits[NUM_TRITS_HASH];
   int msg_len = 0, tag_len = 0;
+  bool raw_message = true;
   status_t ret = SC_OK;
 
   if (json_obj == NULL) {
@@ -288,13 +289,29 @@ status_t ta_send_transfer_req_deserialize(const char* const obj,
     goto done;
   }
 
+  json_result = cJSON_GetObjectItemCaseSensitive(json_obj, "message_format");
+  if (json_result != NULL) {
+    strncmp("trytes", json_result->valuestring, 6);
+    raw_message = false;
+  }
+
   json_result = cJSON_GetObjectItemCaseSensitive(json_obj, "message");
   if (json_result != NULL) {
-    msg_len = strlen(json_result->valuestring);
-    req->msg_len = msg_len * 3;
-    flex_trits_from_trytes(req->message, req->msg_len,
-                           (const tryte_t*)json_result->valuestring, msg_len,
-                           msg_len);
+    if (raw_message) {
+      msg_len = strlen(json_result->valuestring) * 2;
+      req->msg_len = msg_len * 3;
+      tryte_t trytes_buffer[msg_len];
+
+      ascii_to_trytes(json_result->valuestring, trytes_buffer);
+      flex_trits_from_trytes(req->message, req->msg_len, trytes_buffer, msg_len,
+                             msg_len);
+    } else {
+      msg_len = strlen(json_result->valuestring);
+      req->msg_len = msg_len * 3;
+      flex_trits_from_trytes(req->message, req->msg_len,
+                             (const tryte_t*)json_result->valuestring, msg_len,
+                             msg_len);
+    }
   } else {
     // 'message' does not exists, set to DEFAULT_MSG
     req->msg_len = DEFAULT_MSG_LEN * 3;

tests/test_serializer.c

@@ -47,6 +47,7 @@ void test_serialize_ta_generate_address(void) {
 void test_deserialize_ta_send_transfer(void) {
   const char* json =
       "{\"value\":100,"
+      "\"message_format\":\"trytes\","
       "\"message\":\"" TAG_MSG "\",\"tag\":\"" TAG_MSG
       "\","
       "\"address\":\"" TRYTES_81_1 "\"}";