Add support for setting window icon

This adds a new property from Settings:🪟:iconand a Icon struct which can be converted to winit:🪟:Icon.

It also adds code to display this icon in Application::run. Due to the fact that the Icon struct is non copyable, I also had to remove the Copy trait from all Settings, both in `iced` and `iced_winit`.

src/settings.rs

@@ -2,7 +2,7 @@
 use crate::window;
 
 /// The settings of an application.
-#[derive(Debug, Clone, Copy, PartialEq, Eq)]
+#[derive(Debug, Clone, PartialEq, Eq)]
 pub struct Settings<Flags> {
     /// The window settings.
     ///

src/window/settings.rs

@@ -1,5 +1,5 @@
 /// The window settings of an application.
-#[derive(Debug, Clone, Copy, PartialEq, Eq)]
+#[derive(Debug, Clone, PartialEq, Eq)]
 pub struct Settings {
     /// The initial size of the window.
     pub size: (u32, u32),
@@ -15,6 +15,9 @@ pub struct Settings {
 
     /// Whether the window should have a border, a title bar, etc. or not.
     pub decorations: bool,
+
+    /// The window icon, which is also usually used in the taskbar
+    pub icon: Option<iced_winit::settings::Icon>,
 }
 
 impl Default for Settings {
@@ -25,6 +28,7 @@ impl Default for Settings {
             max_size: None,
             resizable: true,
             decorations: true,
+            icon: None,
         }
     }
 }
@@ -38,6 +42,7 @@ impl From<Settings> for iced_winit::settings::Window {
             max_size: settings.max_size,
             resizable: settings.resizable,
             decorations: settings.decorations,
+            icon: settings.icon,
             platform_specific: Default::default(),
         }
     }