### 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)

struct {
				float modulation[4];
				union {
					float msdf[4];
					float ninepatch_margins[4];
				};
				float dst_rect[4];
				float src_rect[4];
				float pad[2];
			};
			
			struct {
				float points[6]; 
				float uvs[6]; 
				uint32_t colors[6]; 
			};
		};
		float color_texture_pixel_size[2];
		uint32_t lights[4];
	};
	Item *items[MAX_RENDER_ITEMS];
	bool using_directional_lights = false;
	RID default_canvas_texture;
	RID default_canvas_group_shader;
	RID default_canvas_group_material;
	RID default_clip_children_material;
	RID default_clip_children_shader;
	RS::CanvasItemTextureFilter default_filter = RS::CANVAS_ITEM_TEXTURE_FILTER_LINEAR;
	RS::CanvasItemTextureRepeat default_repeat = RS::CANVAS_ITEM_TEXTURE_REPEAT_DISABLED;
	RID _create_base_uniform_set(RID p_to_render_target, bool p_backbuffer);