added underdeveloped but working image support (no freeing or samplers)

src/core/rect.rs

@@ -1,4 +1,4 @@
-use crate::{primitive::RoundedRectData, Painter, UiNum, UiColor, Widget};
+use crate::{Painter, UiColor, UiNum, Widget, render::RectPrimitive};
 
 #[derive(Clone, Copy)]
 pub struct Rect {
@@ -29,7 +29,7 @@ impl Rect {
 
 impl<Ctx> Widget<Ctx> for Rect {
     fn draw(&self, painter: &mut Painter<Ctx>) {
-        painter.write(RoundedRectData {
+        painter.write(RectPrimitive {
             color: self.color,
             radius: self.radius,
             thickness: self.thickness,