### 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.renames["SCREEN_UV"] = "screen_uv";
		actions.renames["SCREEN_TEXTURE"] = "screen_texture";
		actions.renames["SCREEN_PIXEL_SIZE"] = "canvas_data.screen_pixel_size";
		actions.renames["FRAGCOORD"] = "gl_FragCoord";
		actions.renames["POINT_COORD"] = "gl_PointCoord";
		actions.renames["INSTANCE_ID"] = "gl_InstanceIndex";
		actions.renames["VERTEX_ID"] = "gl_VertexIndex";
		actions.renames["LIGHT_POSITION"] = "light_position";
		actions.renames["LIGHT_DIRECTION"] = "light_direction";
		actions.renames["LIGHT_IS_DIRECTIONAL"] = "is_directional";
		actions.renames["LIGHT_COLOR"] = "light_color";
		actions.renames["LIGHT_ENERGY"] = "light_energy";
		actions.renames["LIGHT"] = "light";
		actions.renames["SHADOW_MODULATE"] = "shadow_modulate";
		actions.renames["texture_sdf"] = "texture_sdf";
		actions.renames["texture_sdf_normal"] = "texture_sdf_normal";
		actions.renames["sdf_to_screen_uv"] = "sdf_to_screen_uv";
		actions.renames["screen_uv_to_sdf"] = "screen_uv_to_sdf";
		actions.usage_defines["COLOR"] = "#define COLOR_USED\n";
		actions.usage_defines["SCREEN_TEXTURE"] = "#define SCREEN_TEXTURE_USED\n";
		actions.usage_defines["SCREEN_UV"] = "#define SCREEN_UV_USED\n";
		actions.usage_defines["SCREEN_PIXEL_SIZE"] = "@SCREEN_UV";
		actions.usage_defines["NORMAL"] = "#define NORMAL_USED\n";
		actions.usage_defines["NORMAL_MAP"] = "#define NORMAL_MAP_USED\n";
		actions.usage_defines["LIGHT"] = "#define LIGHT_SHADER_CODE_USED\n";
		actions.usage_defines["SPECULAR_SHININESS"] = "#define SPECULAR_SHININESS_USED\n";
		actions.render_mode_defines["skip_vertex_transform"] = "#define SKIP_TRANSFORM_USED\n";
		actions.render_mode_defines["unshaded"] = "#define MODE_UNSHADED\n";
		actions.render_mode_defines["light_only"] = "#define MODE_LIGHT_ONLY\n";
		actions.custom_samplers["TEXTURE"] = "texture_sampler";