### 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)

{
			Vector<RD::AttachmentFormat> attachments;
			RD::AttachmentFormat af_color;
			af_color.format = RD::DATA_FORMAT_R8_UNORM;
			af_color.usage_flags = RD::TEXTURE_USAGE_SAMPLING_BIT | RD::TEXTURE_USAGE_STORAGE_BIT | RD::TEXTURE_USAGE_COLOR_ATTACHMENT_BIT;
			attachments.push_back(af_color);
			shadow_render.sdf_framebuffer_format = RD::get_singleton()->framebuffer_format_create(attachments);
		}
		
		Vector<RD::VertexAttribute> vf;
		RD::VertexAttribute vd;
		vd.format = sizeof(real_t) == sizeof(float) ? RD::DATA_FORMAT_R32G32B32_SFLOAT : RD::DATA_FORMAT_R64G64B64_SFLOAT;
		vd.location = 0;
		vd.offset = 0;
		vd.stride = sizeof(real_t) * 3;
		vf.push_back(vd);
		shadow_render.vertex_format = RD::get_singleton()->vertex_format_create(vf);
		vd.format = sizeof(real_t) == sizeof(float) ? RD::DATA_FORMAT_R32G32_SFLOAT : RD::DATA_FORMAT_R64G64_SFLOAT;
		vd.stride = sizeof(real_t) * 2;
		vf.write[0] = vd;
		shadow_render.sdf_vertex_format = RD::get_singleton()->vertex_format_create(vf);
		shadow_render.shader_version = shadow_render.shader.version_create();
		for (int i = 0; i < 3; i++) {
			RD::PipelineRasterizationState rs;
			rs.cull_mode = i == 0 ? RD::POLYGON_CULL_DISABLED : (i == 1 ? RD::POLYGON_CULL_FRONT : RD::POLYGON_CULL_BACK);
			RD::PipelineDepthStencilState ds;
			ds.enable_depth_write = true;
			ds.enable_depth_test = true;
			ds.depth_compare_operator = RD::COMPARE_OP_LESS;
			shadow_render.render_pipelines[i] = RD::get_singleton()->render_pipeline_create(shadow_render.shader.version_get_shader(shadow_render.shader_version, SHADOW_RENDER_MODE_SHADOW), shadow_render.framebuffer_format, shadow_render.vertex_format, RD::RENDER_PRIMITIVE_TRIANGLES, rs, RD::PipelineMultisampleState(), ds, RD::PipelineColorBlendState::create_disabled(), 0);