### 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)

singleton = nullptr;
	GLES3::MaterialStorage *material_storage = GLES3::MaterialStorage::get_singleton();
	material_storage->shaders.canvas_shader.version_free(data.canvas_shader_default_version);
	shadow_render.shader.version_free(shadow_render.shader_version);
	material_storage->material_free(default_canvas_group_material);
	material_storage->shader_free(default_canvas_group_shader);
	material_storage->material_free(default_clip_children_material);
	material_storage->shader_free(default_clip_children_shader);
	singleton = nullptr;
	glDeleteBuffers(1, &data.canvas_quad_vertices);
	glDeleteVertexArrays(1, &data.canvas_quad_array);
	glDeleteBuffers(1, &data.canvas_quad_vertices);
	glDeleteVertexArrays(1, &data.canvas_quad_array);
	GLES3::TextureStorage::get_singleton()->canvas_texture_free(default_canvas_texture);
	memdelete_arr(state.instance_data_array);
	memdelete_arr(state.light_uniforms);
	if (state.shadow_fb != 0) {
		glDeleteFramebuffers(1, &state.shadow_fb);
		glDeleteTextures(1, &state.shadow_texture);
		glDeleteRenderbuffers(1, &state.shadow_depth_buffer);
		state.shadow_fb = 0;
		state.shadow_texture = 0;
		state.shadow_depth_buffer = 0;
	}
}
#endif