LibWeb: Implement CanvasRenderingContext2D.restore()

Author: https://github.com/linusg
Commit: 3e0e965f24
Pull-request: https://github.com/SerenityOS/serenity/pull/11444

Userland/Libraries/LibWeb/HTML/CanvasRenderingContext2D.idl

@@ -32,6 +32,7 @@ interface CanvasRenderingContext2D {
     undefined putImageData(ImageData imagedata, double dx, double dy);
 
     undefined save();
+    undefined restore();
 
     readonly attribute HTMLCanvasElement canvas;