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.
query_processing_stage,
                &global_context->getSettingsRef(),
                &global_context->getClientInfo(),
                true,
                [&](const Progress & progress) { onProgress(progress); });
            if (send_external_tables)
                sendExternalTables(parsed_query);
            receiveResult(parsed_query);
            break;
        }
        catch (const Exception & e)
        {
            /// Retry when the server said "Client should retry" and no rows
            /// has been received yet.
             && e.code() == ErrorCodes::DEADLOCK_AVOIDED && --retries_left)
            {
                std::cerr << "Got a transient error from the server, will"
                        << " retry (" << retries_left << " retries left)";
            }
            else
            {
                throw;
            }
        }
    }
    assert(retries_left > 0);
}
/// Receives and processes packets coming from server.
/// Also checks if query execution should be cancelled.
void ClientBase::receiveResult(ASTPtr parsed_query)