CPU usage is misreported.

Currently "0 CPU" means "no CPU metric received in the previous ProfileEvents packet". But there can be many ProfileEvents packets and only a few with CPU increment.

That's why the CPU metric shows something weird like:
```
0
0
0
0
0
1234
0
0
0
...
```

This is unbearable, and the CPU metric should be either fixed or removed altogether.
// Check whether the error (or its absence) matches the test hints
                // (or their absence).
                hint = true;
                if 
                {
                    if (test_hint.serverError())
                    {
                        if (!server_exception)
                        {
                            es_hint = false;
                            fmt::print(stderr, "Expected server error code '{}' but got no server error (query: {}).\n",
                                       test_hint.serverError(), full_query);
                        }
                        else if (server_exception->code() != test_hint.serverError())
                        {
                            es_hint = false;
                            fmt::print(stderr, "Expected server error code: {} but got: {} (query: {}).\n",
                                       test_hint.serverError(), server_exception->code(), full_query);
                        }
                    }
                    if (test_hint.clientError())
                    {
                        if (!client_exception)
                        {
                            es_hint = false;
                            fmt::print(stderr, "Expected client error code '{}' but got no client error (query: {}).\n",
                                       test_hint.clientError(), full_query);
                        }
                        else if (client_exception->code() != test_hint.clientError())
                        {