configuration: Initial work to reset all settings

This commit does not compile.

Initial work to add and connect a Reset to Defaults button to the
configure_general tab.

Co-authored-by: german77 <juangerman-13@hotmail.com>

src/yuzu/configuration/configure_general.h

@@ -24,6 +24,7 @@ public:
     explicit ConfigureGeneral(QWidget* parent = nullptr);
     ~ConfigureGeneral() override;
 
+    void ResetDefaults();
     void ApplyConfiguration();
 
 private: