citra-qt: Add /default parsing for hotkeys. Also minor code cleanups.

src/citra_qt/configuration/configure_input.h

@@ -41,15 +41,14 @@ public:
     void loadConfiguration();
     void EmitInputKeysChanged();
 
+    /// Save the current input profile index
+    void ApplyProfile();
 public slots:
     void OnHotkeysChanged(QList<QKeySequence> new_key_list);
 
 signals:
     void InputKeysChanged(QList<QKeySequence> new_key_list);
 
-    // Save the current input profile index
-    void ApplyProfile();
-
 private:
     std::unique_ptr<Ui::ConfigureInput> ui;