### 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)

}
	pb.vertex_format_id = vertex_id;
	PolygonID id = polygon_buffers.last_id++;
	polygon_buffers.polygons[id] = pb;
	return id;
}
void RendererCanvasRenderRD::free_polygon(PolygonID p_polygon) {
	PolygonBuffers *pb_ptr = polygon_buffers.polygons.getptr(p_polygon);
	ERR_FAIL_COND(!pb_ptr);
	PolygonBuffers &pb = *pb_ptr;
	if (pb.indices.is_valid()) {
		RD::get_singleton()->free(pb.indices);
	}
	if (pb.index_buffer.is_valid()) {
		RD::get_singleton()->free(pb.index_buffer);
	}
	RD::get_singleton()->free(pb.vertex_array);
	RD::get_singleton()->free(pb.vertex_buffer);
	polygon_buffers.polygons.erase(p_polygon);
}
void RendererCanvasRenderRD::_bind_canvas_texture(RD::DrawListID p_draw_list, RID p_texture, RS::CanvasItemTextureFilter p_base_filter, RS::CanvasItemTextureRepeat p_base_repeat, RID &r_last_texture, PushConstant &push_constant, Size2 &r_texpixel_size) {
	if (p_texture == RID()) {
		p_texture = default_canvas_texture;
	}
	if (r_last_texture == p_texture) {
		return; 
	}
	RID uniform_set;
	Color specular_shininess;
	Size2i size;