Define a format for the configuration metadata and tool to rerun a job from it

Following the conversation in https://github.com/key4hep/k4FWCore/issues/329#issuecomment-2988673619 and https://github.com/key4hep/k4FWCore/pull/329#issuecomment-2990054786, it would be good to define a format for the configuration metadata, possibly together with a tool to run jobs from it that would need to parse it.