Image _handleImageFrame execute twice when has cache

## 🐛 Bug Report

Image _handleImageFrame execute twice when has cache, it's not happend on Image.network, because MultiImageStreamCompleter addListener not check currentImage.

```
// MultiFrameImageStreamCompleter
@override
void addListener(ImageStreamListener listener) {
if (!hasListeners && _codec != null && (_currentImage == null || _codec!.frameCount > 1))
_decodeNextFrameAndSchedule();
super.addListener(listener);
}

// MultiImageStreamCompleter
@override
void addListener(ImageStreamListener listener) {
if (!hasListeners && _codec != null) _decodeNextFrameAndSchedule();
super.addListener(listener);
}
```

### Expected behavior

### Reproduction steps

### Configuration

**Version:** 3.1.0

**Platform:**
- [ ] :iphone: iOS
- [ ] :robot: Android