QtGUI: Add buttton to toggle the filter.

src/yuzu/main.h

@@ -302,6 +302,7 @@ private:
     void MigrateConfigFiles();
     void UpdateWindowTitle(std::string_view title_name = {}, std::string_view title_version = {},
                            std::string_view gpu_vendor = {});
+    void UpdateFilterText();
     void UpdateStatusBar();
     void UpdateGPUAccuracyButton();
     void UpdateStatusButtons();
@@ -336,6 +337,7 @@ private:
     QPushButton* gpu_accuracy_button = nullptr;
     QPushButton* renderer_status_button = nullptr;
     QPushButton* dock_status_button = nullptr;
+    QPushButton* filter_status_button = nullptr;
     QTimer status_bar_update_timer;
 
     std::unique_ptr<Config> config;