feat(fs): Cross-Compatible Emulator Save Pathing w/ Custom Save Paths

Signed-off-by: Collecting <collecting@noreply.localhost>

src/frontend_common/config.h

@@ -53,6 +53,9 @@ protected:
 
     void Reload();
 
+    void ReadMirrorValues();
+    void SaveMirrorValues();
+
     /**
      * Derived config classes must implement this so they can reload all platform-specific
      * values and global ones.