### Godot version

4.0 beta 10

### System information

Windows 10, Vulkan Renderer

### Issue description

In 2D scenes with sprites, when the sprite's `flip_h` and/or `flip_v` property is enabled, the normal map is flipped with the image, causing lighting to be reversed. While this does technically make sense, in a game where You have a bunch of sprites that flip and use normal maps, the only solution is to generate normal maps for both facing directions.
![image](https://user-images.githubusercontent.com/47702559/209426338-6257d66c-a965-4793-a7bb-5a635a136267.png)

Ultimately the fix is simple: Invert the red channel in normal maps on horizontally flipped sprites, and invert the green channel on vertically flipped sprites.

### Steps to reproduce

1) Create a Sprite2D
2) Add a Diffuse Texture and Normal Map 
3) Add a 2D Light to the scene
4) Enable `flip_h` and/or `flip_v` on the Sprite2D

### Minimal reproduction project

[Normal not flipped.zip](https://github.com/godotengine/godot/files/10298203/Normal.not.flipped.zip)

data.max_instances_per_batch = 128;
	} else {
		data.max_lights_per_render = 256;
		data.max_instances_per_batch = 2048;
	}
	
	data.max_instances_per_buffer = MAX(data.max_instances_per_batch, uint32_t(GLOBAL_GET("rendering/gl_compatibility/item_buffer_size")));
	data.max_instance_buffer_size = data.max_instances_per_buffer * sizeof(InstanceData); 
	state.canvas_instance_data_buffers.resize(3);
	state.canvas_instance_batches.reserve(200);
	for (int i = 0; i < 3; i++) {
		GLuint new_buffers[3];
		glGenBuffers(3, new_buffers);
		
		glBindBuffer(GL_ARRAY_BUFFER, new_buffers[0]);
		glBufferData(GL_ARRAY_BUFFER, data.max_instance_buffer_size, nullptr, GL_STREAM_DRAW);
		
		glBindBuffer(GL_UNIFORM_BUFFER, new_buffers[1]);
		glBufferData(GL_UNIFORM_BUFFER, sizeof(LightUniform) * data.max_lights_per_render, nullptr, GL_STREAM_DRAW);
		
		glBindBuffer(GL_UNIFORM_BUFFER, new_buffers[2]);
		glBufferData(GL_UNIFORM_BUFFER, sizeof(StateBuffer), nullptr, GL_STREAM_DRAW);
		DataBuffer db;
		db.buffer = new_buffers[0];
		db.light_ubo = new_buffers[1];
		db.state_ubo = new_buffers[2];
		db.last_frame_used = 0;
		db.fence = glFenceSync(GL_SYNC_GPU_COMMANDS_COMPLETE, 0);
		state.canvas_instance_data_buffers[i] = db;
	}