Loading saved images with stretched config doesn't work

Try passing this object in the `data` field when the constructor is called with `const editor = new EditorJS({}))`

```json
{
"time": 1600668389224,
"blocks": [
{
"type": "image",
"data": {
"url": "https://cdn.pixabay.com/photo/2017/09/01/21/53/blue-2705642_1280.jpg",
"caption": "Here is a caption field",
"withBorder": false,
"withBackground": true,
"stretched": false
}
},
{
"type": "paragraph",
"data": {
"text": "hellow orld"
}
},
{
"type": "paragraph",
"data": {
"text": "hello world"
}
},
{
"type": "image",
"data": {
"url": "https://cdn.pixabay.com/photo/2017/09/01/21/53/blue-2705642_1280.jpg",
"caption": "adsad",
"withBorder": false,
"withBackground": false,
"stretched": true
}
}
],
"version": "2.18.0"
}
```

The third block, i.e. paragraph ' hello world ' will get the `ce-block--stretched` class applied to it and the image below it won't.

But, the settings icon for stretched is toggled. Other settings work fine.

What's the issue?