[iOS] Image.HeightRequest not respected when Image added in an Horizontal StackLayout

### Description

Adding an `Image` in an horizontal `StackLayout` and setting the Image's `HeightRequest` to
something different than the underlying image Height is rendered differently on iOS and Android.

On iOS, Image in an horizontal StackLayout does not respect HeightRequest and always shows
the image with its original size.

On Android, the Image is scaled correctly with regard to the HeightRequest property.

This is not an issue when using vertical `StackLayout` or `Grid`.

### Steps to Reproduce

* Create a `StackLayout` with Horizontal orientation
* Add an `Image` children to the StackLayout and set its `HeightRequest` to something else
than its original height.

OR

Run the attached sample on iOS and Android and compare the rendered views. (See screenshots below)

 

### Link to public reproduction project repository

https://github.com/durandt/maui-issue4-ios-image-in-horizontal-stack-layout

### Version with bug

7.0 (current)

### Last version that worked well

Unknown/Other

### Affected platforms

iOS

### Affected platform versions

iOS16.2

### Did you find any workaround?

Avoid wrapping Images in horizontal StackLayouts

### Relevant log output

_No response_

Start with the linked reproduction project and run it on iOS and Android, comparing the Image inside a horizontal StackLayout with its HeightRequest set differently from the source image height. Trace the iOS layout behavior responsible for sizing the Image; done means the iOS rendering respects HeightRequest like Android without regressing vertical StackLayout or Grid behavior.

Written by the indexing model from the issue text.