
This change adds new helpers that, taken together, allow to resume the flows having nothing but flow detail at hands. First one, load_from_factory, gets flow factory function as a parameter and saves its fully qualified name and arguments to flow metadata. Others can be used to re-create the flow using that metadata, and load it into engine. Change-Id: Ia3cd989b3b0388ec0a9f09fe527f768eec5cc904