### 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)

PIPELINE_LIGHT_MODE_DISABLED,
		PIPELINE_LIGHT_MODE_ENABLED,
		PIPELINE_LIGHT_MODE_MAX
	};
	struct PipelineVariants {
		PipelineCacheRD variants[PIPELINE_LIGHT_MODE_MAX][PIPELINE_VARIANT_MAX];
	};
	struct {
		CanvasShaderRD canvas_shader;
		RID default_version;
		RID default_version_rd_shader;
		RID quad_index_buffer;
		RID quad_index_array;
		PipelineVariants pipeline_variants;
		ShaderCompiler compiler;
	} shader;
	struct CanvasShaderData : public RendererRD::MaterialStorage::ShaderData {
		enum BlendMode {