message: Format use declarations in `image::viewer`
diff: use crate::backend::{self, Backend};
  use crate::{Primitive, Renderer};
  -use iced_native::{
  - image::{self, viewer},
  - mouse, Rectangle, Vector,
  -};
  +use iced_native::image;
  +use iced_native::image::viewer;
  +use iced_native::mouse;
  +use iced_native::{Rectangle, Vector};
  impl<B> viewer::Renderer for Renderer<B>
  where
  