Function duckdb_logical_type_get_alias 

pub unsafe extern "C" fn duckdb_logical_type_get_alias(
    type_: duckdb_logical_type,
) -> *mut c_char

Returns the alias of a duckdb_logical_type, if set, else nullptr. The result must be destroyed with duckdb_free.

@param type The logical type @return The alias or nullptr