chore: improve table level schemas

[achettyiitr]

Description

• Adding an index for the latest table schemas (destination_id, namespace, table_name, source_id DESC).
• https://www.notion.so/rudderstacks/Warehouse-indexing-263f2b415dd08049a3f4f781f0bf087d?source=copy_link#278f2b415dd080b7a261e606d976d373

Linear Ticket

• Resolves WAR-1186

Security

• The code changed/added as part of this pull request won't create any security issues with how the software is being used.

[shekhar-rudder]

Should we call the index "latest"? If we add another index in the future, it might be confusing

[codecov]

Codecov Report

✅ All modified and coverable lines are covered by tests.
✅ Project coverage is 77.60%. Comparing base (9017582) to head (1ec62af).

Additional details and impacted files

@@            Coverage Diff             @@
##           master    #6398      +/-   ##
==========================================
- Coverage   77.64%   77.60%   -0.04%     
==========================================
  Files         523      523              
  Lines       70313    70313              
==========================================
- Hits        54593    54569      -24     
- Misses      12879    12913      +34     
+ Partials     2841     2831      -10     

☔ View full report in Codecov by Sentry.
📢 Have feedback on the report? Share it here.

🚀 New features to boost your workflow:

• ❄️ Test Analytics: Detect flaky tests, report on failures, and find test suite problems.