Purpose

Reduce memory footprint between postgres data retrieval and elasticsearch indexing

Approach

Remove Entity intermediaries on call number conversion in extractor.
Use separate method in MultiTenantSearchDocumentConverter since reindexing requires less steps.
Remove reference to "_new" from ResourceEvent in SearchDocumentConverter as soon as it's not needed to allow early garbage collection
Remove duplicate conversion from sub resource repositories and optimize map usage.
Fix reindex persisting in InstanceChildrenResourceService to avoid tenant update operation on call numbers
Remove String intermediary in JsonConverter when converting object to bytes
Pass CharacterStream reader from sub-resource repositories to json converter to remove String intermediary while converting "instances" from result set to list of maps

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