feat(ingest): add support for aliases in plugin registry

[hsheth2]

Used for a deprecation warning + easy transition with snowflake-beta

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 (metadata ingestion)

       8 files  ±0         8 suites  ±0   59m 53s ⏱️ + 2m 46s
   708 tests ±0     705 ✔️ ±0  3 💤 ±0  0 ❌ ±0 
1 418 runs  ±0  1 412 ✔️ ±0  6 💤 ±0  0 ❌ ±0 

Results for commit 03960c1. ± Comparison against base commit f70bb20.

[github-actions]

Unit Test Results (build & test)

571 tests  ±0   571 ✔️ ±0   14m 30s ⏱️ +3s
141 suites ±0       0 💤 ±0 
141 files   ±0       0 ❌ ±0 

Results for commit 03960c1. ± Comparison against base commit f70bb20.

[shirshanka]

LGTM