### 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)

shadow_render.shader.version_set_uniform(CanvasOcclusionShaderGLES3::MODELVIEW1, modelview.columns[0][0], modelview.columns[1][0], 0, modelview.columns[2][0], shadow_render.shader_version, variant);
		shadow_render.shader.version_set_uniform(CanvasOcclusionShaderGLES3::MODELVIEW2, modelview.columns[0][1], modelview.columns[1][1], 0, modelview.columns[2][1], shadow_render.shader_version, variant);
		if (co->cull_mode != cull_mode) {
			if (co->cull_mode == RS::CANVAS_OCCLUDER_POLYGON_CULL_DISABLED) {
				glDisable(GL_CULL_FACE);
			} else {
				if (cull_mode == RS::CANVAS_OCCLUDER_POLYGON_CULL_DISABLED) {
					
					glEnable(GL_CULL_FACE);
				}
				glCullFace(co->cull_mode == RS::CANVAS_OCCLUDER_POLYGON_CULL_CLOCKWISE ? GL_FRONT : GL_BACK);
			}
			cull_mode = co->cull_mode;
		}
		glBindVertexArray(co->vertex_array);
		glDrawElements(GL_TRIANGLES, 3 * co->line_point_count, GL_UNSIGNED_SHORT, 0);
		instance = instance->next;
	}
	Transform2D to_shadow;
	to_shadow.columns[0].x = 1.0 / -(half_size * 2.0);
	to_shadow.columns[2].x = 0.5;
	cl->shadow.directional_xform = to_shadow * to_light_xform;
	glBindVertexArray(0);
	glBindFramebuffer(GL_FRAMEBUFFER, 0);
	glDepthMask(GL_FALSE);
	glDisable(GL_DEPTH_TEST);
	glDisable(GL_SCISSOR_TEST);
	glDisable(GL_CULL_FACE);
}
void RasterizerCanvasGLES3::_update_shadow_atlas() {