Support playing roms by dragging into window

src/window.rs

@@ -1,4 +1,4 @@
-use std::sync::Arc;
+use std::{path::PathBuf, sync::Arc};
 
 pub use about::AboutWindow;
 use egui::{Ui, ViewportBuilder};
@@ -47,6 +47,10 @@ pub trait AppWindow {
         let _ = event;
         false
     }
+    fn handle_dropped_file(&mut self, path: PathBuf) -> bool {
+        let _ = path;
+        false
+    }
 }
 
 pub struct InitArgs<'a> {