### 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)

}
			CanvasLight *clight = canvas_light_owner.get_or_null(l->light_internal);
			if (!clight) { 
				l->render_index_cache = -1;
				l = l->next_ptr;
				ERR_CONTINUE(!clight);
			}
			Transform2D to_light_xform = (p_canvas_transform * l->light_shader_xform).affine_inverse();
			Vector2 canvas_light_pos = p_canvas_transform.xform(l->xform.get_origin()); 
			state.light_uniforms[index].position[0] = canvas_light_pos.x;
			state.light_uniforms[index].position[1] = canvas_light_pos.y;
			_update_transform_2d_to_mat2x4(to_light_xform, state.light_uniforms[index].matrix);
			_update_transform_2d_to_mat2x4(l->xform_cache.affine_inverse(), state.light_uniforms[index].shadow_matrix);
			state.light_uniforms[index].height = l->height * (p_canvas_transform.columns[0].length() + p_canvas_transform.columns[1].length()) * 0.5; 
			for (int i = 0; i < 4; i++) {
				state.light_uniforms[index].shadow_color[i] = uint8_t(CLAMP(int32_t(l->shadow_color[i] * 255.0), 0, 255));
				state.light_uniforms[index].color[i] = l->color[i];
			}
			state.light_uniforms[index].color[3] = l->energy; 
			if (state.shadow_fb != 0) {
				state.light_uniforms[index].shadow_pixel_size = (1.0 / state.shadow_texture_size) * (1.0 + l->shadow_smooth);
				state.light_uniforms[index].shadow_z_far_inv = 1.0 / clight->shadow.z_far;
				state.light_uniforms[index].shadow_y_ofs = clight->shadow.y_offset;
			} else {
				state.light_uniforms[index].shadow_pixel_size = 1.0;
				state.light_uniforms[index].shadow_z_far_inv = 1.0;
				state.light_uniforms[index].shadow_y_ofs = 0;
			}
			state.light_uniforms[index].flags = l->blend_mode << LIGHT_FLAGS_BLEND_SHIFT;
			state.light_uniforms[index].flags |= l->shadow_filter << LIGHT_FLAGS_FILTER_SHIFT;