[Feature] support image resizing on CfProperties

### Is there an existing issue for this?

- [x] I have searched the existing issues

### Description

Here's how an image resizing request looks like in JS:

```js
await fetch(url, {
cf: {image: {width: w, height: h, quality: q, fit: 'scale-down'}},
})
```

There are a few more of the within 'image' key. Here's the JS docs:

https://developers.cloudflare.com/workers//runtime-apis/request#requestinitcfproperties

and

https://developers.cloudflare.com/images/image-resizing/resize-with-workers

Adding support basically just means setting the according props on the JsValue in request_init.rs, right? And adding them in CfProperties.