Add database and worker health endpoints

[ThomasLaPiana]

Closes #3912

Description Of Changes

After removing the more robust/verbose healthchecks, we've found that they were actually useful and should be reinstated for debugging use as discrete endpoints that don't affect the general latency of /health

Code Changes

• add a new healthcheck for the database at health/database and restore functionality to check migration status
• add a new healthcheck for the workesr at health/workers and restore the previous functionality
• slim down the existing health endpoint

Steps to Confirm

• run the server with nox -s dev and verify the 3 endpoints in your browser/HTTP requester (/health, /health/database, /health/workers)

Pre-Merge Checklist

• All CI Pipelines Succeeded
• Issue Requirements are Met
• Update CHANGELOG.md
• For API changes, the Postman collection has been updated

[cypress]

Passing run #3662 ↗︎

0	4	0	0	0
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Details:

Merge 4711ed7 into 7bef8b4...
Project: fides	Commit: 867678b038 ℹ️
Status: Passed	Duration: 01:23 💡
Started: Aug 21, 2023 9:58 PM	Ended: Aug 21, 2023 9:59 PM

_{This comment has been generated by cypress-bot as a result of this project's GitHub integration settings.}

[codecov]

Codecov Report

Patch coverage: 74.28% and project coverage change: -0.05% ⚠️

Comparison is base (7bef8b4) 87.40% compared to head (4711ed7) 87.35%.

Additional details and impacted files

@@            Coverage Diff             @@
##             main    #3947      +/-   ##
==========================================
- Coverage   87.40%   87.35%   -0.05%     
==========================================
  Files         318      318              
  Lines       19509    19533      +24     
  Branches     2504     2507       +3     
==========================================
+ Hits        17051    17063      +12     
- Misses       2024     2034      +10     
- Partials      434      436       +2     

Files Changed	Coverage Δ
src/fides/api/db/database.py	78.87% <40.00%> (-9.01%)	⬇️
src/fides/api/api/v1/endpoints/health.py	86.20% <88.00%> (-6.11%)	⬇️

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[adamsachs]

lgtm! i like the approach of decoupling the potentially more complex health checks from the straightforward heartbeat: gives us that level of detail if needed, while keeping the heartbeat as lightweight as possible.

also, thanks for switching over to the shared API db session that respects the configured connection pool! 👍

[ThomasLaPiana]

FYI @daveqnet this should also remedy the connection pool woes we've been having and should close this issue:

#3918

However we can wait to confirm before closing it