Move Debugger and Windowed to a better location

We move `renderer::Debugger` to `layout::Debugger` and
`renderer::Windowed` to `window::Renderer`.

native/src/renderer/debugger.rs

@@ -1,26 +0,0 @@
-use crate::{Color, Layout, Point, Widget};
-
-/// A renderer able to graphically explain a [`Layout`].
-///
-/// [`Layout`]: ../struct.Layout.html
-pub trait Debugger: super::Renderer {
-    /// Explains the [`Layout`] of an [`Element`] for debugging purposes.
-    ///
-    /// This will be called when [`Element::explain`] has been used. It should
-    /// _explain_ the given [`Layout`] graphically.
-    ///
-    /// A common approach consists in recursively rendering the bounds of the
-    /// [`Layout`] and its children.
-    ///
-    /// [`Layout`]: struct.Layout.html
-    /// [`Element`]: struct.Element.html
-    /// [`Element::explain`]: struct.Element.html#method.explain
-    fn explain<Message>(
-        &mut self,
-        defaults: &Self::Defaults,
-        widget: &dyn Widget<Message, Self>,
-        layout: Layout<'_>,
-        cursor_position: Point,
-        color: Color,
-    ) -> Self::Output;
-}

native/src/renderer/windowed.rs

@@ -1,58 +0,0 @@
-use crate::MouseCursor;
-
-use raw_window_handle::HasRawWindowHandle;
-
-/// A renderer that can target windows.
-pub trait Windowed: super::Renderer + Sized {
-    /// The settings of the renderer.
-    type Settings: Default;
-
-    /// The type of target.
-    type Target: Target<Renderer = Self>;
-
-    /// Creates a new [`Windowed`] renderer.
-    ///
-    /// [`Windowed`]: trait.Windowed.html
-    fn new(settings: Self::Settings) -> Self;
-
-    /// Performs the drawing operations described in the output on the given
-    /// target.
-    ///
-    /// The overlay can be a bunch of debug text logs. It should be rendered on
-    /// top of the GUI on most scenarios.
-    fn draw<T: AsRef<str>>(
-        &mut self,
-        output: &Self::Output,
-        overlay: &[T],
-        target: &mut Self::Target,
-    ) -> MouseCursor;
-}
-
-/// A rendering target.
-pub trait Target {
-    /// The renderer of this target.
-    type Renderer;
-
-    /// Creates a new rendering [`Target`] from the given window handle, width,
-    /// height and dpi factor.
-    ///
-    /// [`Target`]: trait.Target.html
-    fn new<W: HasRawWindowHandle>(
-        window: &W,
-        width: u16,
-        height: u16,
-        dpi: f32,
-        renderer: &Self::Renderer,
-    ) -> Self;
-
-    /// Resizes the current [`Target`].
-    ///
-    /// [`Target`]: trait.Target.html
-    fn resize(
-        &mut self,
-        width: u16,
-        height: u16,
-        dpi: f32,
-        renderer: &Self::Renderer,
-    );
-}