### 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
Vector<String> components = String(p_name).split("/", true, 2);
	if (p_name == "format") {
		r_ret = FORMAT_3; 
		return true;
	} else if (components.size() == 2 && components[0].begins_with("layer_") && components[0].trim_prefix("layer_").is_valid_int()) {
		int index = components[0].trim_prefix("layer_").to_int();
		if (index < 0 || index >= (int)layers.size()) {
			return false;
		}
		if (components[1] == "name") {
			r_ret = get_layer_name(index);
			return true;
		} else if (components[1] == "enabled") {
			r_ret = is_layer_enabled(index);
			return true;
		} else if (components[1] == "modulate") {
			r_ret = get_layer_modulate(index);
			return true;
		} else if (components[1] == "y_sort_enabled") {
			r_ret = is_layer_y_sort_enabled(index);