iOS Next Entry to skip hidden parents

[tj-devel709]

Description of Change

We have a bug in iOS when using an Entry's Next ReturnType. If the next 'available' entry/editor is not visible, we skip it and go on to the next available entry/editor. However, if the parent of the next 'available' entry/editor is not visible and the 'available' entry/editor is not marked as not visible, we will still go into it.

In the search for the next entry/editor, we go through the current controls siblings, then go up a level to the parent's siblings and look into their children. Because of this, we can simply check if the parent is visible and go onto the next parent if so.

Before	After
HiddenEntry-Before.mov	HiddenEntry-After.mov

Code Snippet from original issue (click me!)

<?xml version="1.0" encoding="utf-8" ?>
<ContentPage xmlns="http://schemas.microsoft.com/dotnet/2021/maui"
             xmlns:x="http://schemas.microsoft.com/winfx/2009/xaml"
             x:Class="MauiApp1.MainPage">
    <ScrollView>
        <VerticalStackLayout Padding="30,0" Spacing="25">
            <Entry Placeholder="entry1" ReturnType="Next"/>

            <Grid IsVisible="False">
                <Entry x:Name="hiddenEntry2" Placeholder="hiddenEntry2" ReturnType="Next" Focused="HiddenEntry2Focused"/>
            </Grid>

            <Entry Placeholder="entry3" ReturnType="Next" Focused="Entry3Focused"/>
        </VerticalStackLayout>
    </ScrollView>
</ContentPage>

namespace MauiApp1
{
    public partial class MainPage : ContentPage
    {
        public MainPage()
        {
            InitializeComponent();
        }

        private void HiddenEntry2Focused(object sender, FocusEventArgs e)
        {
            Console.WriteLine("Hidden entry: IsVisible: " + hiddenEntry2.IsVisible);
        }

        private void Entry3Focused(object sender, FocusEventArgs e)
        {
            Console.WriteLine("Hidden entry: IsVisible: " + hiddenEntry2.IsVisible);
        }
    }
}

Issues Fixed

Fixes #19139