### 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)

state.current_batch_index = 0;
		state.canvas_instance_batches.clear();
		return;
	}
	
	glBindBuffer(GL_ARRAY_BUFFER, state.canvas_instance_data_buffers[state.current_buffer].buffer);
#ifdef WEB_ENABLED
	glBufferSubData(GL_ARRAY_BUFFER, r_last_index * sizeof(InstanceData), sizeof(InstanceData) * index, state.instance_data_array);
#else
	
	void *buffer = glMapBufferRange(GL_ARRAY_BUFFER, r_last_index * sizeof(InstanceData), index * sizeof(InstanceData), GL_MAP_WRITE_BIT | GL_MAP_UNSYNCHRONIZED_BIT);
	memcpy(buffer, state.instance_data_array, index * sizeof(InstanceData));
	glUnmapBuffer(GL_ARRAY_BUFFER);
#endif
	glDisable(GL_SCISSOR_TEST);
	current_clip = nullptr;
	GLES3::CanvasShaderData::BlendMode last_blend_mode = GLES3::CanvasShaderData::BLEND_MODE_MIX;
	state.current_tex = RID();
	for (uint32_t i = 0; i <= state.current_batch_index; i++) {
		
		if (current_clip != state.canvas_instance_batches[i].clip) {
			current_clip = state.canvas_instance_batches[i].clip;
			if (current_clip) {
				glEnable(GL_SCISSOR_TEST);
				glScissor(current_clip->final_clip_rect.position.x, current_clip->final_clip_rect.position.y, current_clip->final_clip_rect.size.x, current_clip->final_clip_rect.size.y);
			} else {
				glDisable(GL_SCISSOR_TEST);
			}
		}