### 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)

ERR_FAIL_COND(!state.canvas_instance_batches[state.current_batch_index].command);
	
	static const GLenum prim[5] = { GL_POINTS, GL_LINES, GL_LINE_STRIP, GL_TRIANGLES, GL_TRIANGLE_STRIP };
	_bind_canvas_texture(state.canvas_instance_batches[p_index].tex, state.canvas_instance_batches[p_index].filter, state.canvas_instance_batches[p_index].repeat);
	switch (state.canvas_instance_batches[p_index].command_type) {
		case Item::Command::TYPE_RECT:
		case Item::Command::TYPE_NINEPATCH: {
			glBindVertexArray(data.indexed_quad_array);
			glBindBuffer(GL_ARRAY_BUFFER, state.canvas_instance_data_buffers[state.current_buffer].buffer);
			uint32_t range_start = state.canvas_instance_batches[p_index].start * sizeof(InstanceData);
			_enable_attributes(range_start, false);
			glDrawElementsInstanced(GL_TRIANGLES, 6, GL_UNSIGNED_INT, 0, state.canvas_instance_batches[p_index].instance_count);
			glBindVertexArray(0);
		} break;
		case Item::Command::TYPE_POLYGON: {
			const Item::CommandPolygon *polygon = static_cast<const Item::CommandPolygon *>(state.canvas_instance_batches[p_index].command);
			PolygonBuffers *pb = polygon_buffers.polygons.getptr(polygon->polygon.polygon_id);
			ERR_FAIL_COND(!pb);
			glBindVertexArray(pb->vertex_array);
			glBindBuffer(GL_ARRAY_BUFFER, state.canvas_instance_data_buffers[state.current_buffer].buffer);
			uint32_t range_start = state.canvas_instance_batches[p_index].start * sizeof(InstanceData);
			_enable_attributes(range_start, false);
			if (pb->color_disabled && pb->color != Color(1.0, 1.0, 1.0, 1.0)) {
				glVertexAttrib4f(RS::ARRAY_COLOR, pb->color.r, pb->color.g, pb->color.b, pb->color.a);
			}
			if (pb->index_buffer != 0) {
				glDrawElementsInstanced(prim[polygon->primitive], pb->count, GL_UNSIGNED_INT, nullptr, 1);
			} else {
				glDrawArraysInstanced(prim[polygon->primitive], 0, pb->count, 1);