### 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<uint8_t> index_buffer;
		index_buffer.resize(p_indices.size() * sizeof(int32_t));
		{
			uint8_t *w = index_buffer.ptrw();
			memcpy(w, p_indices.ptr(), sizeof(int32_t) * p_indices.size());
		}
		glGenBuffers(1, &pb.index_buffer);
		glBindBuffer(GL_ELEMENT_ARRAY_BUFFER, pb.index_buffer);
		glBufferData(GL_ELEMENT_ARRAY_BUFFER, p_indices.size() * 4, index_buffer.ptr(), GL_STATIC_DRAW);
		pb.count = p_indices.size();
	}
	glBindVertexArray(0);
	glBindBuffer(GL_ARRAY_BUFFER, 0);
	glBindBuffer(GL_ELEMENT_ARRAY_BUFFER, 0);
	PolygonID id = polygon_buffers.last_id++;
	polygon_buffers.polygons[id] = pb;
	return id;
}
void RasterizerCanvasGLES3::free_polygon(PolygonID p_polygon) {
	PolygonBuffers *pb_ptr = polygon_buffers.polygons.getptr(p_polygon);
	ERR_FAIL_COND(!pb_ptr);
	PolygonBuffers &pb = *pb_ptr;
	if (pb.index_buffer != 0) {
		glDeleteBuffers(1, &pb.index_buffer);
	}
	glDeleteVertexArrays(1, &pb.vertex_array);
	glDeleteBuffers(1, &pb.vertex_buffer);
	polygon_buffers.polygons.erase(p_polygon);
}
void RasterizerCanvasGLES3::_allocate_instance_data_buffer() {