### 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)

GLES3::CanvasMaterialData *material_data = state.canvas_instance_batches[i].material_data;
		CanvasShaderGLES3::ShaderVariant variant = state.canvas_instance_batches[i].shader_variant;
		uint64_t specialization = 0;
		specialization |= uint64_t(state.canvas_instance_batches[i].lights_disabled);
		specialization |= uint64_t(!GLES3::Config::get_singleton()->float_texture_supported) << 1;
		RID shader_version = data.canvas_shader_default_version;
		if (material_data) {
			if (material_data->shader_data->version.is_valid() && material_data->shader_data->valid) {
				
				material_data->bind_uniforms();
				shader_version = material_data->shader_data->version;
			}
		}
		bool success = GLES3::MaterialStorage::get_singleton()->shaders.canvas_shader.version_bind_shader(shader_version, variant, specialization);
		if (!success) {
			continue;
		}
		GLES3::CanvasShaderData::BlendMode blend_mode = state.canvas_instance_batches[i].blend_mode;
		if (last_blend_mode != blend_mode) {
			if (last_blend_mode == GLES3::CanvasShaderData::BLEND_MODE_DISABLED) {
				
				glEnable(GL_BLEND);
			} else if (blend_mode == GLES3::CanvasShaderData::BLEND_MODE_DISABLED) {
				
				glDisable(GL_BLEND);
			}
			switch (blend_mode) {
				case GLES3::CanvasShaderData::BLEND_MODE_DISABLED: {
					
				} break;