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.
{
    connection->sendCancel();
    if (is_interactive)
    {
        progress_indication.clearProgressOutput();
        std::cout << "Cancelling query." << std::endl;
    }
    cancelled = true;
}
void ClientBase::processParsedSingleQuery(const String & full_query, const String & query_to_execute,