Function forest_filecoin::daemon::db_util::import_chain_as_forest_car

pub async fn import_chain_as_forest_car(
    from_path: &Path,
    forest_car_db_dir: &Path,
    import_mode: ImportMode,
) -> Result<(PathBuf, Tipset)>

This function validates and stores the CAR binary from from_path(either local path or URL) into the {DB_ROOT}/car_db/ (automatically trans-code into .forest.car.zst format when needed), and returns its final file path and the heaviest tipset.