fix(indexing): Memory management improvements

[viacheslavkol]

Purpose

Reduce memory footprint between postgres data retrieval and elasticsearch indexing

Approach

Remove String intermediary in JsonConverter when converting object to bytes
Remove reference to "_new" from ResourceEvent in SearchDocumentConverter as soon as it's not needed to allow garbage collaction

Changes Checklist

• API Changes: Document any API paths, methods, request or response bodies changed, added, or removed.
• Database Schema Changes: Indicate any database schema changes and their impact. Confirm that migration scripts were created.
• Interface Version Changes: Indicate any changes to interface versions.
• Interface Dependencies: Document added or removed dependencies.
• Permissions: Document any changes to permissions.
• Logging: Confirm that logging is appropriately handled.
• Unit Testing: Confirm that changed classes were covered by unit tests.
• Integration Testing: Confirm that changed logic was covered by integration tests.
• Manual Testing: Confirm that changes were tested on local or dev environment.
• NEWS: Confirm that the NEWS file is updated with relevant information about the changes made in this pull request.

Related Issues

MSEARCH-1184
PERF-1236

[sonarqubecloud]

Quality Gate failed

Failed conditions
73.5% Coverage on New Code (required ≥ 80%)

See analysis details on SonarQube Cloud