### 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)

push_constant.lights[1] = 0;
	push_constant.lights[2] = 0;
	push_constant.lights[3] = 0;
	uint32_t base_flags = 0;
	uint16_t light_count = 0;
	PipelineLightMode light_mode;
	{
		Light *light = p_lights;
		while (light) {
			if (light->render_index_cache >= 0 && p_item->light_mask & light->item_mask && p_item->z_final >= light->z_min && p_item->z_final <= light->z_max && p_item->global_rect_cache.intersects_transformed(light->xform_cache, light->rect_cache)) {
				uint32_t light_index = light->render_index_cache;
				push_constant.lights[light_count >> 2] |= light_index << ((light_count & 3) * 8);
				light_count++;
				if (light_count == MAX_LIGHTS_PER_ITEM) {
					break;
				}
			}
			light = light->next_ptr;
		}
		base_flags |= light_count << FLAGS_LIGHT_COUNT_SHIFT;
	}
	light_mode = (light_count > 0 || using_directional_lights) ? PIPELINE_LIGHT_MODE_ENABLED : PIPELINE_LIGHT_MODE_DISABLED;
	PipelineVariants *pipeline_variants = p_pipeline_variants;
	bool reclip = false;
	RID last_texture;
	Size2 texpixel_size;
	bool skipping = false;
	const Item::Command *c = p_item->commands;
	while (c) {
		if (skipping && c->type != Item::Command::TYPE_ANIMATION_SLICE) {