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.
#include "ProgressIndication.h"
#include <algorithm>
#include <cstddef>
#include <numeric>
#include <cmath>
#include <IO/WriteBufferFromFileDescriptor.h>
#include <base/types.h>
#include "Common/formatReadable.h"
#include <Common/TerminalSize.h>
#include <Common/UnicodeBar.h>
#include "IO/WriteBufferFromString.h"
#include <Databases/DatabaseMemory.h>
namespace
{
    constexpr UInt64 ALL_THREADS = 0;
    double calculateCPUUsage(DB::ThreadIdToTimeMap times, UInt64 elapsed)