### 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
output = Vector2i(output.x - output.y / 2, output.x + output.y / 2);
				}
			} else {
				if (output.y % 2) {
					if (output.y < 0) {
						output = Vector2i(output.x + output.y / 2, -output.x + output.y / 2 - 1);
					} else {
						output = Vector2i(output.x + output.y / 2 + 1, -output.x + output.y / 2);
					}
				} else {
					output = Vector2i(output.x + output.y / 2, -output.x + output.y / 2);
				}
			}
			break;
	}
	if (p_offset_axis == TileSet::TILE_OFFSET_AXIS_VERTICAL) {
		SWAP(output.x, output.y);
	}
	return output;
}
int TileMap::get_effective_quadrant_size(int p_layer) const {
	ERR_FAIL_INDEX_V(p_layer, (int)layers.size(), 1);
	
	if (is_y_sort_enabled() && layers[p_layer].y_sort_enabled) {
		return 1;
	} else {
		return quadrant_size;
	}
}
void TileMap::set_selected_layer(int p_layer_id) {