[Proposal] API that allows developers to hook a media element event and know the full screen status.

### Feature name

VideoPlayer_FullScreenStatusChanged

### Link to discussion

https://github.com/CommunityToolkit/Maui/discussions/1748#discussioncomment-9548965

### Progress tracker

- [x] Android Implementation
- [x] iOS Implementation
- [x] MacCatalyst Implementation
- [x] Windows Implementation
- [ ] Tizen Implementation
- [ ] Unit Tests
- [x] Samples
- [x] Documentation

### Summary

API that allows developers to hook a media element event and know the full screen status.
Is it full screen or normal ?

### Motivation

In Xamarin times, we already have something to control when the Full Screen status changed (first and third party) and now we have a very mature Media Element in MAUI is about time to start with this.

### Detailed Design

```cs
///
/// Backing store for the property.
///
public static readonly BindableProperty FullScreenProperty =
BindableProperty.Create(nameof(FullScreenState), typeof(MediaElementScreenState), typeof(MediaElement),
MediaElementScreenState.Default, propertyChanged: OnFullScreenPropertyChanged);
```

### Usage Syntax

```cs
public MediaElementPage(MediaElementViewModel viewModel, ILogger logger) : base(viewModel)
{
InitializeComponent();
MediaElement.FullScreenStateChanged += MediaElement_FullScreenStateChanged;
}

void MediaElement_FullScreenStateChanged(object? sender, FullScreenStateChangedEventArgs e) =>
logger.LogInformation("FullScreen State Changed. Old State: {PreviousState}, New State: {NewState}", e.PreviousState, e.NewState);
```

### Drawbacks

I don't see any reason to not do it :)

### Alternatives

Before I migrate to MAUI MediaElement I was using Xamarin with Xamarians/MediaPlayer [https://github.com/Xamarians/MediaPlayer] , looks simple enough from a use perspective:

```cs
public partial class SegnalesEnVivoPage : ContentPage
{
InitializeComponent();
BindingContext = new SegnalesEnVivoViewModel();

VideoPlayer.FullScreenStatusChanged += VideoPlayer_FullScreenStatusChanged;
}

private void VideoPlayer_FullScreenStatusChanged(object sender, bool value)
{
NavigationPage.SetHasNavigationBar(this, !value);
Shell.SetNavBarIsVisible(this, !value);
frmInformation.IsVisible = !value;
frmBackground.IsVisible = !value;
frmPlayer.Margin = value ? new Thickness(0, 0, 0, 0) : new Thickness(10, 20, 10, 10);
VideoPlayer.HeightRequest = value ? deviceScreenHeight : 240;
InvalidateMeasure();
}

}
```

### Unresolved Questions

Perhaps the above API is a good v1 if it works on all platforms?
And then we iterate on more functionality in later versions?