Minor - Adds target FPS control to engine settings - V14.5.0

Adds functionality to control the target FPS of the engine via the ImGui settings panel.

This includes:
- Adding target FPS variables and accessors in the application class.
- Adding a set_target_fps function to the fps_limiter class.
- Updating the ImGui engine settings panel to include a target FPS setting.
- Modifying the main loop to make use of the fps limiter and the engine target FPS.

enginecustom/src/inc/system/application_class.h

@@ -483,6 +483,17 @@ public:
 	 */
 	float get_screen_near() const { return screen_near; }
 
+	/**
+	 * Get the target fps for the application.
+	 * @return The target fps as an integer.
+	 */
+	int get_target_fps() const { return target_fps_; };
+	/**
+	 * Set the target fps for the application.
+	 * @param target_fps The new target fps as an integer.
+	 */
+	void set_target_fps(int target_fps) { target_fps_ = target_fps; };
+
 	
 private:
 	/**
@@ -690,6 +701,7 @@ private :
 	ID3D11ShaderResourceView* back_buffer_srv_;
 
 	stats* stats_;
+	int target_fps_ = 60;
 
 	// ------------------------------------------------- //
 	// ------------------- Culling --------------------- //