### 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)

_EIDX(0, 1), _EIDX(0, 2), _EIDX(1, 2),
			_EIDX(1, 2), _EIDX(1, 1), _EIDX(0, 1),
			_EIDX(0, 2), _EIDX(0, 3), _EIDX(1, 3),
			_EIDX(1, 3), _EIDX(1, 2), _EIDX(0, 2),
			
			_EIDX(1, 0), _EIDX(1, 1), _EIDX(2, 1),
			_EIDX(2, 1), _EIDX(2, 0), _EIDX(1, 0),
			
			
			
			_EIDX(1, 2), _EIDX(1, 3), _EIDX(2, 3),
			_EIDX(2, 3), _EIDX(2, 2), _EIDX(1, 2),
			
			_EIDX(2, 0), _EIDX(2, 1), _EIDX(3, 1),
			_EIDX(3, 1), _EIDX(3, 0), _EIDX(2, 0),
			_EIDX(2, 1), _EIDX(2, 2), _EIDX(3, 2),
			_EIDX(3, 2), _EIDX(3, 1), _EIDX(2, 1),
			_EIDX(2, 2), _EIDX(2, 3), _EIDX(3, 3),
			_EIDX(3, 3), _EIDX(3, 2), _EIDX(2, 2),
			
			_EIDX(1, 1), _EIDX(1, 2), _EIDX(2, 2),
			_EIDX(2, 2), _EIDX(2, 1), _EIDX(1, 1)
		};
#undef _EIDX
		glBufferData(GL_ELEMENT_ARRAY_BUFFER, sizeof(elems), elems, GL_STATIC_DRAW);
		glBindBuffer(GL_ELEMENT_ARRAY_BUFFER, 0);
	}
	int uniform_max_size = config->max_uniform_buffer_size;
	if (uniform_max_size < 65536) {
		data.max_lights_per_render = 64;