### 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)

if (np->draw_center) {
					push_constant.flags |= FLAGS_NINEPACH_DRAW_CENTER;
				}
				push_constant.ninepatch_margins[0] = np->margin[SIDE_LEFT];
				push_constant.ninepatch_margins[1] = np->margin[SIDE_TOP];
				push_constant.ninepatch_margins[2] = np->margin[SIDE_RIGHT];
				push_constant.ninepatch_margins[3] = np->margin[SIDE_BOTTOM];
				RD::get_singleton()->draw_list_set_push_constant(p_draw_list, &push_constant, sizeof(PushConstant));
				RD::get_singleton()->draw_list_bind_index_array(p_draw_list, shader.quad_index_array);
				RD::get_singleton()->draw_list_draw(p_draw_list, true);
				
				push_constant.color_texture_pixel_size[0] = texpixel_size.x;
				push_constant.color_texture_pixel_size[1] = texpixel_size.y;
			} break;
			case Item::Command::TYPE_POLYGON: {
				const Item::CommandPolygon *polygon = static_cast<const Item::CommandPolygon *>(c);
				PolygonBuffers *pb = polygon_buffers.polygons.getptr(polygon->polygon.polygon_id);
				ERR_CONTINUE(!pb);
				
				{
					static const PipelineVariant variant[RS::PRIMITIVE_MAX] = { PIPELINE_VARIANT_ATTRIBUTE_POINTS, PIPELINE_VARIANT_ATTRIBUTE_LINES, PIPELINE_VARIANT_ATTRIBUTE_LINES_STRIP, PIPELINE_VARIANT_ATTRIBUTE_TRIANGLES, PIPELINE_VARIANT_ATTRIBUTE_TRIANGLE_STRIP };
					ERR_CONTINUE(polygon->primitive < 0 || polygon->primitive >= RS::PRIMITIVE_MAX);
					RID pipeline = pipeline_variants->variants[light_mode][variant[polygon->primitive]].get_render_pipeline(pb->vertex_format_id, p_framebuffer_format);
					RD::get_singleton()->draw_list_bind_render_pipeline(p_draw_list, pipeline);
				}
				if (polygon->primitive == RS::PRIMITIVE_LINES) {
					
					
				}