### 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)

light_count = index;
	}
	if (light_count > 0) {
		RD::get_singleton()->buffer_update(state.lights_uniform_buffer, 0, sizeof(LightUniform) * light_count, &state.light_uniforms[0]);
	}
	{
		
		State::Buffer state_buffer;
		Size2i ssize = texture_storage->render_target_get_size(p_to_render_target);
		Transform3D screen_transform;
		screen_transform.translate_local(-(ssize.width / 2.0f), -(ssize.height / 2.0f), 0.0f);
		screen_transform.scale(Vector3(2.0f / ssize.width, 2.0f / ssize.height, 1.0f));
		_update_transform_to_mat4(screen_transform, state_buffer.screen_transform);
		_update_transform_2d_to_mat4(p_canvas_transform, state_buffer.canvas_transform);
		Transform2D normal_transform = p_canvas_transform;
		normal_transform.columns[0].normalize();
		normal_transform.columns[1].normalize();
		normal_transform.columns[2] = Vector2();
		_update_transform_2d_to_mat4(normal_transform, state_buffer.canvas_normal_transform);
		state_buffer.canvas_modulate[0] = p_modulate.r;
		state_buffer.canvas_modulate[1] = p_modulate.g;
		state_buffer.canvas_modulate[2] = p_modulate.b;
		state_buffer.canvas_modulate[3] = p_modulate.a;
		Size2 render_target_size = texture_storage->render_target_get_size(p_to_render_target);
		state_buffer.screen_pixel_size[0] = 1.0 / render_target_size.x;
		state_buffer.screen_pixel_size[1] = 1.0 / render_target_size.y;
		state_buffer.time = state.time;
		state_buffer.use_pixel_snap = p_snap_2d_vertices_to_pixel;
		state_buffer.directional_light_count = directional_light_count;
		Vector2 canvas_scale = p_canvas_transform.get_scale();