[frontend] Remove QDockWidget Wait Tree (#2949)

No one uses it and knows how to use it. So, remove it and replace it later with something more useful :)

Reviewed-on: https://git.eden-emu.dev/eden-emu/eden/pulls/2949
Reviewed-by: crueter <crueter@eden-emu.dev>
Reviewed-by: MaranBr <maranbr@eden-emu.dev>
Reviewed-by: Caio Oliveira <caiooliveirafarias0@gmail.com>
Co-authored-by: unknown <sahyno1996@gmail.com>
Co-committed-by: unknown <sahyno1996@gmail.com>

src/yuzu/main.h

@@ -390,7 +390,6 @@ private slots:
     void OnToggleFilterBar();
     void OnToggleStatusBar();
     void OnGameListRefresh();
-    void OnDisplayTitleBars(bool);
     void InitializeHotkeys();
     void ToggleFullscreen();
     bool UsingExclusiveFullscreen();
@@ -535,7 +534,6 @@ private:
     QString startup_icon_theme;
 
     // Debugger panes
-    WaitTreeWidget* waitTreeWidget;
     ControllerDialog* controller_dialog;
 
     QAction* actions_recent_files[max_recent_files_item];