Add tracing & cache control the express server and observe queries in…

… GraphiQL #graphql-in-production

[API]

### Instructions
1. Activate the `tracing` & `cacheControl` option on Apollo Server
2. Run some operations in GraphiQL and inspect results
---
### Tips
- Edit `api/src/server/index.js`
- `tracing` & `cacheControl` options are `Boolean`: you need to set it to `true`

api/src/server/index.js

@@ -107,6 +107,8 @@ const startServer = async () => {
           ...req.context,
         },
         debug: true,
+        tracing: true,
+        cacheControl: true,
       }))(req, res, next);
     })(req, res, next);
   });