### Godot version

v4.0.beta11.official [91713ced8]

### System information

MX Linux 21

### Issue description

In Godot 3, TileMap had methods get_used_cells() and get_used_cells_by_id(). Godot 4's TileMap only has get_used_cells() and is missing get_used_cells_by_id().

get_used_cells_by_id() is highly useful in multiple cases, for example when trying to get all cells that are of road type, to randomly spawn a car.

Re-implementing get_used_cells_by_id() should be simple. The method could simply call get_used_cells(), and ignore all cells that are of the wrong ID.

### Steps to reproduce

N/A

### Minimal reproduction project

N/A
continue;
				}
				TileSetAtlasSource *atlas_source = Object::cast_to<TileSetAtlasSource>(source);
				if (atlas_source) {
					
					const TileData *tile_data;
					if (q.runtime_tile_data_cache.has(E_cell.value)) {
						tile_data = q.runtime_tile_data_cache[E_cell.value];
					} else {
						tile_data = atlas_source->get_tile_data(c.get_atlas_coords(), c.alternative_tile);
					}
					Ref<Material> mat = tile_data->get_material();
					int tile_z_index = tile_data->get_z_index();
					
					Vector2 tile_position = map_to_local(q.coords * get_effective_quadrant_size(q.layer));
					if (is_y_sort_enabled() && layers[q.layer].y_sort_enabled) {
						
						tile_position.y += layers[q.layer].y_sort_origin + tile_data->get_y_sort_origin();
					}
					
					
					RID ci;
					
					if (prev_ci == RID() || prev_material != mat || prev_z_index != tile_z_index) {
						
						ci = rs->canvas_item_create();
						if (mat.is_valid()) {
							rs->canvas_item_set_material(ci, mat->get_rid());
						}
						rs->canvas_item_set_parent(ci, layers[q.layer].canvas_item);