[Bug] series `sampling` breaks `updateAxisPointer` action

### Version

5.5.0

### Link to Minimal Reproduction

https://jsfiddle.net/86yt7Lr1/

### Steps to Reproduce

1. Create chart with `line` type series and use `sampling: 'lttb'`.
2. Have data size large enougth to trigger downsampling. i.e. ~ 2x pixel width
3. Call `chart.dispatchAction({type:'updateAxisPointer', dataIndex: })`
4. Fails when dataIndex is "downsampled"

### Current Behavior

The axispointer is not triggered some % of the time (depending on level of downsampling).

### Expected Behavior

Work regardless of the use of `sampling` in the series options.

### Environment

```markdown
- OS: any
- Browser: any
- Framework: none
```

### Any additional comments?

I think the issue might be in https://github.com/apache/echarts/blob/c576f0c395ef9af87461fe93bcaa4490d89a331a/src/data/DataStore.ts#L550-L565

There is an effort to binary search for the correct index but it only works if it finds an exact match. Otherwise it falls through and returns -1 to indicate the value was not found and nothing works. If this function returned the closest index instead, then it would work.