Added the bones of test_serialize_json

veilid-core/src/veilid_api/tests/mod.rs

@@ -1 +1,2 @@
+pub mod test_serialize_json;
 pub mod test_serialize_rkyv;

veilid-core/src/veilid_api/tests/test_serialize_json.rs

@@ -0,0 +1,3 @@
+pub async fn test_all() {
+    // test_simple_string().await;
+}