### 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)

glBindBuffer(GL_ARRAY_BUFFER, 0);
	glBindBuffer(GL_UNIFORM_BUFFER, 0);
	state.instance_data_array = memnew_arr(InstanceData, data.max_instances_per_buffer);
	state.light_uniforms = memnew_arr(LightUniform, data.max_lights_per_render);
	{
		const uint32_t indices[6] = { 0, 2, 1, 3, 2, 0 };
		glGenVertexArrays(1, &data.indexed_quad_array);
		glBindVertexArray(data.indexed_quad_array);
		glBindBuffer(GL_ARRAY_BUFFER, data.canvas_quad_vertices);
		glGenBuffers(1, &data.indexed_quad_buffer);
		glBindBuffer(GL_ELEMENT_ARRAY_BUFFER, data.indexed_quad_buffer);
		glBufferData(GL_ELEMENT_ARRAY_BUFFER, sizeof(uint32_t) * 6, indices, GL_STATIC_DRAW);
		glBindVertexArray(0);
	}
	String global_defines;
	global_defines += "#define MAX_GLOBAL_SHADER_UNIFORMS 256\n"; 
	global_defines += "#define MAX_LIGHTS " + itos(data.max_lights_per_render) + "\n";
	global_defines += "#define MAX_DRAW_DATA_INSTANCES " + itos(data.max_instances_per_batch) + "\n";
	GLES3::MaterialStorage::get_singleton()->shaders.canvas_shader.initialize(global_defines, 1);
	data.canvas_shader_default_version = GLES3::MaterialStorage::get_singleton()->shaders.canvas_shader.version_create();
	shadow_render.shader.initialize();
	shadow_render.shader_version = shadow_render.shader.version_create();
	{
		default_canvas_group_shader = material_storage->shader_allocate();
		material_storage->shader_initialize(default_canvas_group_shader);
		material_storage->shader_set_code(default_canvas_group_shader, R"(
// Default CanvasGroup shader.
shader_type canvas_item;
void fragment() {
	vec4 c = textureLod(SCREEN_TEXTURE, SCREEN_UV, 0.0);