Rename iced_virtual to iced_pure

`virtual` is a reserved keyword in Rust 😬

virtual/src/widget.rs

@@ -1,73 +0,0 @@
-mod button;
-mod column;
-mod element;
-mod text;
-mod tree;
-
-pub use button::Button;
-pub use column::Column;
-pub use element::Element;
-pub use text::Text;
-pub use tree::Tree;
-
-use iced_native::event::{self, Event};
-use iced_native::layout::{self, Layout};
-use iced_native::mouse;
-use iced_native::renderer;
-use iced_native::{Clipboard, Hasher, Length, Point, Rectangle, Shell};
-
-use std::any::{self, Any};
-
-pub trait Widget<Message, Renderer> {
-    fn tag(&self) -> any::TypeId;
-
-    fn state(&self) -> Box<dyn Any>;
-
-    fn children(&self) -> &[Element<Message, Renderer>];
-
-    fn width(&self) -> Length;
-
-    fn height(&self) -> Length;
-
-    fn hash_layout(&self, state: &mut Hasher);
-
-    fn layout(
-        &self,
-        renderer: &Renderer,
-        limits: &layout::Limits,
-    ) -> layout::Node;
-
-    fn draw(
-        &self,
-        state: &Tree<Message, Renderer>,
-        renderer: &mut Renderer,
-        style: &renderer::Style,
-        layout: Layout<'_>,
-        cursor_position: Point,
-        viewport: &Rectangle,
-    );
-
-    fn mouse_interaction(
-        &self,
-        _state: &Tree<Message, Renderer>,
-        _layout: Layout<'_>,
-        _cursor_position: Point,
-        _viewport: &Rectangle,
-        _renderer: &Renderer,
-    ) -> mouse::Interaction {
-        mouse::Interaction::Idle
-    }
-
-    fn on_event(
-        &mut self,
-        _state: &mut Tree<Message, Renderer>,
-        _event: Event,
-        _layout: Layout<'_>,
-        _cursor_position: Point,
-        _renderer: &Renderer,
-        _clipboard: &mut dyn Clipboard,
-        _shell: &mut Shell<'_, Message>,
-    ) -> event::Status {
-        event::Status::Ignored
-    }
-}