Added Essentials AppActions

[cedric56]

✨ Add AppActions support for Avalonia MAUI Essentials (Linux D-Bus integration)

This PR introduces a new AppActions implementation for Avalonia.Controls.Maui.Essentials, enabling Linux desktop integration through D-Bus activation and .desktop file actions.

🚀 Overview

This feature extends MAUI AppActions to support desktop Linux environments when using Avalonia, allowing applications to expose and handle native app shortcuts via:

D-Bus service registration
Dynamic .desktop file generation
Runtime action activation callbacks

✅ Linux Platform Support

Implements PlatformSetAsync for Linux only
Uses OperatingSystem.IsLinux() guard

🔌 D-Bus Integration

Registers a session bus service (com.essentials.AppActions)
Exposes actions via Tmds.DBus
Handles activation through OnAppActionAsync

🖥 Desktop Integration

Generates .desktop files dynamically per app instance
Adds custom Desktop Action entries for each AppAction
Uses gdbus calls to trigger actions externally

🪟 Window Integration

Sets X11 WM_CLASS to support desktop identity binding
Ensures initialization occurs after MainWindow is available

[jsuarezruiz]

This condition excludes only the browser TFM, so the packed net11.0 dependency group now includes Tmds.DBus for every desktop consumer, including Windows and macOS, even though the implementation only supports Linux. This needs a packaging/design decision: avoid flowing the Linux-only dependency to non-Linux consumers, or explicitly accept and document that the shared desktop asset carries it.

[jsuarezruiz]

Could you rebase and fix the conflict? Thanks in advance.

[jsuarezruiz]

CI is currently failing in the ControlGallery NativeAOT publish because AppActionsPage.xaml uses string-path bindings inside the CollectionView item template.

The generated XAML code calls Microsoft.Maui.Controls.Binding.Binding(string, ...), which is marked RequiresUnreferencedCode, so NativeAOT/trimming fails with IL2026:

Using bindings with string paths is not trim safe. Use expression-based binding instead.

Can you review?

[cedric56]

CI is currently failing in the ControlGallery NativeAOT publish because AppActionsPage.xaml uses string-path bindings inside the CollectionView item template.

The generated XAML code calls Microsoft.Maui.Controls.Binding.Binding(string, ...), which is marked RequiresUnreferencedCode, so NativeAOT/trimming fails with IL2026:

Using bindings with string paths is not trim safe. Use expression-based binding instead.

Can you review?

I added a x:DataType to CollectionView ItemTemplate.

[cedric56]

I have added x:DataType="model:AppAction"