iOS: getPicture returns error(null) when specifying PNG an FILE_URI options

# Bug Report

## Problem

### What is expected to happen?

getPicture should return valid file url.

### What does actually happen?

getPicture calls error callback with no error message.

## Information

All specified options for `getPicture`

```ts
quality: 100,
allowEdit: false,
targetWidth: 1000,
targetHeight: 1000,
sourceType: Camera.PictureSourceType.PHOTOLIBRARY,
mediaType: Camera.MediaType.PICTURE,
encodingType: Camera.EncodingType.PNG,
destinationType: Camera.DestinationType.FILE_URI,
```

### Command or Code

Just call `getPicture` with the specified options on iOS device.

### Environment, Platform, Device

Use real iOS device.

### Version information

iOS 16.3.1
cordova-plugin-camera@6.0.0

## Checklist

- [x] I searched for existing GitHub issues
- [x] I updated all Cordova tooling to most recent version
- [x] I included all the necessary information above

---

It seems there's a bug in this place:

https://github.com/apache/cordova-plugin-camera/blob/master/src/ios/CDVCamera.m#L591

Here `self.data` is `nil` then PNG option is picked. That happens, because `self.data` is not assigned above:

https://github.com/apache/cordova-plugin-camera/blob/master/src/ios/CDVCamera.m#L380-L382

So, call to `[self.data mutableCopy]` produces nil, and the next call obviously fails:

https://github.com/apache/cordova-plugin-camera/blob/master/src/ios/CDVCamera.m#L599-L601

It seems that this issue could be easily fixed by assigning `self.data = data` in the mentioned code:

https://github.com/apache/cordova-plugin-camera/blob/master/src/ios/CDVCamera.m#L380-L382

Could you please take a look?

Inspect src/ios/CDVCamera.m around lines 380-382 and 591-601, then reproduce getPicture on a real iOS device with PNG and FILE_URI options. Confirm that the PNG path returns a valid file URL instead of invoking the error callback with a null message.

Written by the indexing model from the issue text.