include fides_key in datamap api output

[SteveDMurphy]

Closes #987

Code Changes

• [x] Include the fides_key for system and dataset rows returned by the /datamap enpoint

Steps to Confirm

• [x] Validate the fides_key of items in the data map
• [ ] Work with frontend to ensure it works for them

Pre-Merge Checklist

• [ ] All CI Pipelines Succeeded
• Documentation Updated:
  • [ ] documentation complete, or draft/outline provided (tag docs-team to complete/review on this branch)
  • [ ] documentation issue created (tag docs-team to complete issue separately)
• [ ] Issue Requirements are Met
• [ ] Relevant Follow-Up Issues Created
• [ ] Update CHANGELOG.md

Description Of Changes

This is not pretty but wanted to get a start out for this quickly as it sounds like a potential blocking item