reorganize reload action, add middle click handler

src/app/browser/window/tab/item/action/reload.rs

@@ -0,0 +1,13 @@
+use gtk::{gio::SimpleAction, glib::uuid_string_random};
+
+pub trait Reload {
+    fn reload() -> Self;
+}
+
+impl Reload for SimpleAction {
+    fn reload() -> Self {
+        let reload = SimpleAction::new(&uuid_string_random(), None);
+        reload.set_enabled(false);
+        reload
+    }
+}