Propagate semantics to CV Item container

[PureWeen]

Description of Change

If you don't set the AutomationProperties on the root element of a templated ListViewItem in WinUI then it just reads out the class type on Narrator. In order to read out something useful the guidance is to set the AutomationProperties of the root element. This PR propagates the semantic properties set on the root xplat element to the ContentControl that acts as the root container for the WinUI CV.

Example Usage

new CollectionView()
{
	ItemsSource = new int[] { 1, 2, 3, 4, 5 },
	ItemTemplate = new DataTemplate(() =>
	{
		var layout = new StackLayout()
		{
			new Button()
			{
				Text = "Whatever"
			}
		};

		SemanticProperties.SetDescription(layout, "Hello there");
		return layout;
	})
};

[rachelkang]

should we consider changing the default too? So that if a developer doesn't explicitly set a description, it'll still make sense?

Maybe we can do something similar to image where it simply can't receive focus at all and won't read out anything - maybe we can make it so just the contents are accessible?

Or alternatively, we can try to make the textual contents or at least the first textual content get propagated upward

[rachelkang]

should we consider changing the default too? So that if a developer doesn't explicitly set a description, it'll still make sense?

Maybe we can do something similar to image where it simply can't receive focus at all and won't read out anything - maybe we can make it so just the contents are accessible?

Or alternatively, we can try to make the textual contents or at least the first textual content get propagated upward

[rachelkang]

LGTM as a first step!

works as expected on Recipes as well :)

[rachelkang]

failing tests unrelated