Redesign iced_wgpu layering architecture

wgpu/src/image/null.rs

@@ -0,0 +1,10 @@
+pub use crate::graphics::Image;
+
+#[derive(Default)]
+pub struct Batch;
+
+impl Batch {
+    pub fn push(&mut self, _image: Image) {}
+
+    pub fn clear(&mut self) {}
+}