[feat:] simple MessageBox-lik naming window

NamingWindow.axaml

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+<Window xmlns="https://github.com/avaloniaui"
+        xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
+        xmlns:d="http://schemas.microsoft.com/expression/blend/2008"
+        xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006"
+        mc:Ignorable="d" d:DesignWidth="800" d:DesignHeight="450"
+        x:Class="Logof_Client.NamingWindow"
+        Title="NamingWindow">
+    <StackPanel Orientation="Vertical">
+        <TextBlock Name="Text" Margin="10" TextWrapping="Wrap" />
+        <TextBox Name="Input" Margin="10" />
+        <StackPanel HorizontalAlignment="Right" Margin="5" Orientation="Horizontal" Name="Buttons">
+            <StackPanel.Styles>
+                <Style Selector="Button">
+                    <Setter Property="Margin" Value="5" />
+                </Style>
+            </StackPanel.Styles>
+        </StackPanel>
+    </StackPanel>
+</Window>

NamingWindow.axaml.cs

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+using System;
+using System.Threading.Tasks;
+using Avalonia.Controls;
+using Avalonia.Markup.Xaml;
+
+namespace Logof_Client;
+
+public partial class NamingWindow : Window
+{
+    public NamingWindow()
+    {
+        AvaloniaXamlLoader.Load(this);
+
+        //InitializeComponent();
+    }
+
+    public static Task<string> Show(Window parent, string input = "", string info = "Bitte geben Sie einen Namen ein:")
+    {
+        try
+        {
+            var wind = new NamingWindow
+            {
+                Title = "Name eingeben"
+            };
+            wind.FindControl<TextBlock>("Text").Text = info;
+            var buttonPanel = wind.FindControl<StackPanel>("Buttons");
+            var inputBox = wind.FindControl<TextBox>("Input");
+
+            inputBox.Text = input;
+            string res = null;
+
+            void AddButton(string caption)
+            {
+                var btn = new Button { Content = caption };
+                btn.Click += (_, __) =>
+                {
+                    res = inputBox.Text;
+                    wind.Close();
+                };
+                buttonPanel.Children.Add(btn);
+            }
+
+            AddButton("Ok");
+
+
+            var tcs = new TaskCompletionSource<string>();
+            wind.Closed += delegate { tcs.TrySetResult(res); };
+            if (parent != null)
+                wind.ShowDialog(parent);
+            else wind.Show();
+
+            return tcs.Task;
+        }
+        catch (Exception ex)
+        {
+            Console.WriteLine("Error while showing naming window: " + ex.Message);
+            return null;
+        }
+    }
+}