Set object name for the graphics debugger

Setting an object name for GPUCommandStreamWidget allows for saving the
graphics debugger's state (if it's show, position, etc). This state is
then restored when restarting the application.

src/citra_qt/debugger/graphics.cpp

@@ -72,7 +72,7 @@ void GPUCommandStreamItemModel::OnGXCommandFinishedInternal(int total_command_co
 
 GPUCommandStreamWidget::GPUCommandStreamWidget(QWidget* parent) : QDockWidget(tr("Graphics Debugger"), parent)
 {
-    // TODO: set objectName!
+    setObjectName("GraphicsDebugger");
 
     GPUCommandStreamItemModel* command_model = new GPUCommandStreamItemModel(this);
     g_debugger.RegisterObserver(command_model);