[MODORDSTOR-527] PO line version history does not consistently highlight Holding changes when changing instance connection with "Find or create"

[ykashtalian]

Purpose

MODORDSTOR-527 - PO line version history does not consistently highlight Holding changes when changing instance connection with "Find or create"

Approach

• In batch mode, the intermediate PO line version is no longer emitted; the direct PATCH transaction produces the single authoritative version.
• The PATCH now re-reads the PO line under SELECT FOR UPDATE inside the transaction and rebases the instance/location changes on that fresh row, preventing the lost update. Existing lock ordering is preserved (pieces -> po_line -> titles).

Pre-Review Checklist

• Self-reviewed Code — Reviewed code for issues, unnecessary parts, and overall quality.
• Change Notes — NEWS.md updated with clear description and issue key.
• Testing — Confirmed changes were tested locally or on dev environment.
• Logging: Confirmed that logging is appropriately handled.
• Breaking Changes — Handled all required actions if changes affect API, DB, or interface versions.
  • API/schema changes
  • Interface version updates
  • DB schema changes / migration scripts
• New Properties / Environment Variables — Updated README.md if new configs were added.

[sonarqubecloud]

Quality Gate passed

Issues
0 New issues
0 Accepted issues

Measures
0 Security Hotspots
87.5% Coverage on New Code
0.0% Duplication on New Code

See analysis details on SonarQube Cloud