Ability to set App ID on Wayland #21783

Is your feature request related to a problem? Please describe.

Currently with the Avalonia.Wayland package, the toplevel app id is unset, which the compositor gets as an empty string. This causes issues when trying to rely on it for window rules and grouping.

Describe the solution you'd like

Adding an AppId property to WaylandPlatformOptions so

.UseWayland()
.With(new WaylandPlatformOptions { AppId = "com.my.app" })

in the app builder sets xdg_toplevel.app_id. Can also default to the assembly name similar to how X11/XWayland sets WmClass.

Describe alternatives you've considered

No response

Additional context

No response