### Godot version

4.1.dev

### System information

Linux Vulkan mobile renderer

### Issue description

In my game I'm using alternatives to create variations of tiles. Because these can't be achieved by changing built-in properties, I'm doing this by attaching a shader with different parameters that will change something in the tile's rendering. However, these differences don't show up in the selection pane at the bottom. Neither in the TileMap editor nor the TileSet editor. This makes it difficult to pick the right one :smile: 

![image](https://github.com/godotengine/godot/assets/43048142/f4b9ffc8-1de2-4693-8fcb-2adcc6f62705)

They do show up in the TileMap editor in the scene view itself, as well as in the game, just not in this preview pane.

### Steps to reproduce

- Create a 2D scene with a TileMap
- Create a TileSet resource and add it
- Add a texture, define a tile
- Create alternatives of this tile, have them use a material with different shaders, or the same shader with different parameters

"Tiles" picker will show them all the same.

### Minimal reproduction project

I am not sure this is necessary as this issue is not specific to any project. If it's desirable I'm happy to create one, though.
Control *base_tiles_drawing_root = nullptr;
	Control *base_tiles_draw = nullptr;
	void _draw_base_tiles();
	Control *base_tiles_texture_grid = nullptr;
	void _draw_base_tiles_texture_grid();
	Control *base_tiles_shape_grid = nullptr;
	void _draw_base_tiles_shape_grid();
	Size2i _compute_base_tiles_control_size();
	
	Control *alternative_tiles_root_control = nullptr;
	void _alternative_tiles_root_control_gui_input(const Ref<InputEvent> &p_event);
	Control *alternative_tiles_drawing_root = nullptr;
	Control *alternatives_draw = nullptr;
	void _draw_alternatives();
	Size2i _compute_alternative_tiles_control_size();
	struct ThemeCache {
		Ref<Texture2D> center_view_icon;
		Ref<Texture2D> checkerboard;
	} theme_cache;
protected:
	virtual void _update_theme_item_cache() override;
	void _notification(int p_what);
	static void _bind_methods();
public:
	
	void set_atlas_source(TileSet *p_tile_set, TileSetAtlasSource *p_tile_set_atlas_source, int p_source_id);
	float get_zoom() const;
	void set_transform(float p_zoom, Vector2i p_panning);
	void set_padding(Side p_side, int p_padding);