### 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)

for (int x = 0; x < 4; x++) {
			push_constant.projection[y * 4 + x] = projection.columns[y][x];
		}
	}
	push_constant.direction[0] = 0.0;
	push_constant.direction[1] = 1.0;
	push_constant.z_far = distance;
	push_constant.pad = 0;
	LightOccluderInstance *instance = p_occluders;
	while (instance) {
		OccluderPolygon *co = occluder_polygon_owner.get_or_null(instance->occluder);
		if (!co || co->index_array.is_null() || !(p_light_mask & instance->light_mask)) {
			instance = instance->next;
			continue;
		}
		_update_transform_2d_to_mat2x4(to_light_xform * instance->xform_cache, push_constant.modelview);
		RD::get_singleton()->draw_list_bind_render_pipeline(draw_list, shadow_render.render_pipelines[co->cull_mode]);
		RD::get_singleton()->draw_list_bind_vertex_array(draw_list, co->vertex_array);
		RD::get_singleton()->draw_list_bind_index_array(draw_list, co->index_array);
		RD::get_singleton()->draw_list_set_push_constant(draw_list, &push_constant, sizeof(ShadowRenderPushConstant));
		RD::get_singleton()->draw_list_draw(draw_list, true);
		instance = instance->next;
	}
	RD::get_singleton()->draw_list_end();
	Transform2D to_shadow;
	to_shadow.columns[0].x = 1.0 / -(half_size * 2.0);
	to_shadow.columns[2].x = 0.5;
	cl->shadow.directional_xform = to_shadow * to_light_xform;
}
void RendererCanvasRenderRD::render_sdf(RID p_render_target, LightOccluderInstance *p_occluders) {