Lister schema: add is_fork and forked_from_url fields
This expands the schema to add fork (boolean yes/no/unknown) and fork source (URL field) if available from the listers, which will be usable for scheduling heuristics (e.g. for GitHub).
Staging instance, all changes can be removed at any time
This expands the schema to add fork (boolean yes/no/unknown) and fork source (URL field) if available from the listers, which will be usable for scheduling heuristics (e.g. for GitHub).