Remove confluent schema registry dependency

[tmnd1991]

Checklist

• The PR conforms to DataHub's Contributing Guideline (particularly Commit Message Format)
• Links to related issues (if applicable)
• Tests for the changes have been added/updated (if applicable)
• Docs related to the changes have been added/updated (if applicable). If a new feature has been added a Usage Guide has been added for the same.
• For any breaking change/potential downtime/deprecation/big changes an entry has been made in Updating DataHub

[github-actions]

Unit Test Results (build & test)

0 tests   - 389   0 ✔️  - 389   0s ⏱️ - 11m 21s
0 suites  -   92   0 💤 ±    0 
0 files    -   92   0 ❌ ±    0 

Results for commit 767d19c. ± Comparison against base commit 9f2b3b9.

[github-actions]

Unit Test Results (metadata ingestion)

       8 files  ±0         8 suites  ±0   1h 15m 59s ⏱️ - 2m 47s
   576 tests ±0     573 ✔️ +2    3 💤 ±0  0 ❌  - 2 
1 090 runs  ±0  1 047 ✔️ +2  43 💤 ±0  0 ❌  - 2 

Results for commit 767d19c. ± Comparison against base commit 9f2b3b9.

[hendrix04]

Any movement on this PR? I am really looking forward to it.

[jjoyce0510]

Hi @tmnd1991 !

Thanks for this contribution. We are going to close this PR until further notice. This is a great start obviously but there's much more work to do to fully remove the registry.

We're still very much interested in removing the registry, so feel free to reopen if you've got time to work on it again!

John