Feature: Expose Rekor entry ID through API

[raghavkaul]

If we can expose the Rekor entry for a scorecard-action run in api.securityscorecards.dev, an end-user would be able to tie back a scorecard run to the scorecard-action run that produced it, instead of trusting that it came from the cron. We could also add the scorecard-action job/run information for transparency.

[naveensrinivasan]

@raghavkaul A good idea. We also serve the results from CRON. Do you have any suggestions for those results?