Fix various copy instead of const ref reported by cppcheck (part 3) (#5616)

* Also remove 2 non declared but defined functions
* Make some functions around const ref changes const

src/client/joystick_controller.h

@@ -149,7 +149,7 @@ class JoystickController {
 	f32 doubling_dtime;
 
 private:
-	void setLayoutFromControllerName(std::string name);
+	void setLayoutFromControllerName(const std::string &name);
 
 	JoystickLayout m_layout;