### 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)

}
		}
		
		RID material = ci->material_owner == nullptr ? ci->material : ci->material_owner->material;
		if (material.is_valid()) {
			GLES3::CanvasMaterialData *md = static_cast<GLES3::CanvasMaterialData *>(material_storage->material_get_data(material, RS::SHADER_CANVAS_ITEM));
			if (md && md->shader_data->valid) {
				if (md->shader_data->uses_screen_texture && canvas_group_owner == nullptr) {
					if (!material_screen_texture_cached) {
						backbuffer_copy = true;
						back_buffer_rect = Rect2();
						backbuffer_gen_mipmaps = md->shader_data->uses_screen_texture_mipmaps;
					} else if (!material_screen_texture_mipmaps_cached) {
						backbuffer_gen_mipmaps = md->shader_data->uses_screen_texture_mipmaps;
					}
				}
				if (md->shader_data->uses_sdf) {
					r_sdf_used = true;
				}
				if (md->shader_data->uses_time) {
					time_used = true;
				}
			}
		}
		if (ci->skeleton.is_valid()) {
			const Item::Command *c = ci->commands;
			while (c) {
				if (c->type == Item::Command::TYPE_MESH) {
					const Item::CommandMesh *cm = static_cast<const Item::CommandMesh *>(c);
					if (cm->mesh_instance.is_valid()) {