### 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)

RendererRD::MeshStorage *mesh_storage = RendererRD::MeshStorage::get_singleton();
	uint32_t vertex_count = p_points.size();
	uint32_t stride = 2; 
	if ((uint32_t)p_colors.size() == vertex_count || p_colors.size() == 1) {
		stride += 4;
	}
	if ((uint32_t)p_uvs.size() == vertex_count) {
		stride += 2;
	}
	if ((uint32_t)p_bones.size() == vertex_count * 4 && (uint32_t)p_weights.size() == vertex_count * 4) {
		stride += 4;
	}
	uint32_t buffer_size = stride * p_points.size();
	Vector<uint8_t> polygon_buffer;
	polygon_buffer.resize(buffer_size * sizeof(float));
	Vector<RD::VertexAttribute> descriptions;
	descriptions.resize(5);
	Vector<RID> buffers;
	buffers.resize(5);
	{
		uint8_t *r = polygon_buffer.ptrw();