### 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)

actions.custom_samplers["NORMAL_TEXTURE"] = "texture_sampler";
		actions.custom_samplers["SPECULAR_SHININESS_TEXTURE"] = "texture_sampler";
		actions.custom_samplers["SCREEN_TEXTURE"] = "material_samplers[3]"; 
		actions.sampler_array_name = "material_samplers";
		actions.base_texture_binding_index = 1;
		actions.texture_layout_set = MATERIAL_UNIFORM_SET;
		actions.base_uniform_string = "material.";
		actions.default_filter = ShaderLanguage::FILTER_LINEAR;
		actions.default_repeat = ShaderLanguage::REPEAT_DISABLE;
		actions.base_varying_index = 4;
		actions.global_buffer_array_variable = "global_shader_uniforms.data";
		shader.compiler.initialize(actions);
	}
	{ 
		Vector<String> versions;
		versions.push_back("\n#define MODE_SHADOW\n"); 
		versions.push_back("\n#define MODE_SDF\n"); 
		shadow_render.shader.initialize(versions);
		{
			Vector<RD::AttachmentFormat> attachments;
			RD::AttachmentFormat af_color;
			af_color.format = RD::DATA_FORMAT_R32_SFLOAT;
			af_color.usage_flags = RD::TEXTURE_USAGE_SAMPLING_BIT | RD::TEXTURE_USAGE_COLOR_ATTACHMENT_BIT;
			attachments.push_back(af_color);
			RD::AttachmentFormat af_depth;
			af_depth.format = RD::DATA_FORMAT_D32_SFLOAT;
			af_depth.usage_flags = RD::TEXTURE_USAGE_DEPTH_STENCIL_ATTACHMENT_BIT;
			attachments.push_back(af_depth);
			shadow_render.framebuffer_format = RD::get_singleton()->framebuffer_format_create(attachments);
		}