### 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, 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, instance_count);
				if (index_array_gl != 0) {
					glBindBuffer(GL_ELEMENT_ARRAY_BUFFER, index_array_gl);
					use_index_buffer = true;
				}
				if (instance_count > 1) {
					if (instance_buffer == 0) {
						break;
					}
					
					glBindBuffer(GL_ARRAY_BUFFER, instance_buffer);
					glEnableVertexAttribArray(1);
					glVertexAttribPointer(1, 4, GL_FLOAT, GL_FALSE, instance_stride * sizeof(float), CAST_INT_TO_UCHAR_PTR(0));
					glVertexAttribDivisor(1, 1);
					glEnableVertexAttribArray(2);
					glVertexAttribPointer(2, 4, GL_FLOAT, GL_FALSE, instance_stride * sizeof(float), CAST_INT_TO_UCHAR_PTR(4 * 4));
					glVertexAttribDivisor(2, 1);
					if (instance_uses_color || instance_uses_custom_data) {
						glEnableVertexAttribArray(5);
						glVertexAttribIPointer(5, 4, GL_UNSIGNED_INT, instance_stride * sizeof(float), CAST_INT_TO_UCHAR_PTR(instance_color_offset * sizeof(float)));
						glVertexAttribDivisor(5, 1);
					}
				}
				GLenum primitive_gl = prim[int(primitive)];
				if (use_index_buffer) {
					glDrawElementsInstanced(primitive_gl, mesh_storage->mesh_surface_get_vertices_drawn_count(surface), mesh_storage->mesh_surface_get_index_type(surface), 0, instance_count);
				} else {
					glDrawArraysInstanced(primitive_gl, 0, mesh_storage->mesh_surface_get_vertices_drawn_count(surface), instance_count);