Make Application and Sandbox return a Result

graphics/src/error.rs

@@ -0,0 +1,7 @@
+/// A graphical error that occurred while running an application.
+#[derive(Debug, thiserror::Error)]
+pub enum Error {
+    /// A suitable graphics adapter or device could not be found
+    #[error("a suitable graphics adapter or device could not be found")]
+    AdapterNotFound,
+}