Implement a "blame" workflow

users looking at a summary should be able to tell how an individual value came to be there. Was it harvested by ScanCode? entered by a human (who contributed, who reviewed, who merged)...

Most of the raw information is there today but needs to be collected and presented together in one place. For example, all of the raw data is retained, and the summarizations for each raw tool is available. Similarly, the curations are all PRs with Git commmits, GitHub comments etc.

All the heavy lifting should be done in the service but the UI needs a way to show the outcome.