### 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.
DRAG_TYPE_NONE,
		DRAG_TYPE_PAN,
	};
	DragType drag_type = DRAG_TYPE_NONE;
	float previous_zoom = 1.0;
	EditorZoomWidget *zoom_widget = nullptr;
	Button *button_center_view = nullptr;
	CenterContainer *center_container = nullptr;
	Vector2 panning;
	void _update_zoom_and_panning(bool p_zoom_on_mouse_pos = false);
	void _zoom_widget_changed();
	void _center_view();
	virtual void gui_input(const Ref<InputEvent> &p_event) override;
	Ref<ViewPanner> panner;
	void _pan_callback(Vector2 p_scroll_vec, Ref<InputEvent> p_event);
	void _zoom_callback(float p_zoom_factor, Vector2 p_origin, Ref<InputEvent> p_event);
	HashMap<Vector2, HashMap<int, Rect2i>> alternative_tiles_rect_cache;
	void _update_alternative_tiles_rect_cache();
	MarginContainer *margin_container = nullptr;
	int margin_container_paddings[4] = { 0, 0, 0, 0 };
	HBoxContainer *hbox = nullptr;
	Label *missing_source_label = nullptr;
	
	Control *background_left = nullptr;
	void _draw_background_left();
	Control *background_right = nullptr;
	void _draw_background_right();
	
	Control *base_tiles_root_control = nullptr;
	void _base_tiles_root_control_gui_input(const Ref<InputEvent> &p_event);