### 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)

dst_rect.size.x *= -1; 
					}
					if (rect->flags & CANVAS_RECT_CLIP_UV) {
						state.instance_data_array[r_index].flags |= FLAGS_CLIP_RECT_UV;
					}
				} else {
					dst_rect = Rect2(rect->rect.position, rect->rect.size);
					if (dst_rect.size.width < 0) {
						dst_rect.position.x += dst_rect.size.width;
						dst_rect.size.width *= -1;
					}
					if (dst_rect.size.height < 0) {
						dst_rect.position.y += dst_rect.size.height;
						dst_rect.size.height *= -1;
					}
					src_rect = Rect2(0, 0, 1, 1);
				}
				if (rect->flags & CANVAS_RECT_MSDF) {
					state.instance_data_array[r_index].flags |= FLAGS_USE_MSDF;
					state.instance_data_array[r_index].msdf[0] = rect->px_range; 
					state.instance_data_array[r_index].msdf[1] = rect->outline; 
					state.instance_data_array[r_index].msdf[2] = 0.f; 
					state.instance_data_array[r_index].msdf[3] = 0.f; 
				} else if (rect->flags & CANVAS_RECT_LCD) {
					state.instance_data_array[r_index].flags |= FLAGS_USE_LCD;
				}
				state.instance_data_array[r_index].modulation[0] = rect->modulate.r * base_color.r;
				state.instance_data_array[r_index].modulation[1] = rect->modulate.g * base_color.g;
				state.instance_data_array[r_index].modulation[2] = rect->modulate.b * base_color.b;
				state.instance_data_array[r_index].modulation[3] = rect->modulate.a * base_color.a;