[MODORDSTOR-500] Use GET /locale to get tenant language & locale setting selections

[SerhiiNosko]

Purpose

https://folio-org.atlassian.net/browse/MODORDSTOR-500

Approach

Provide a brief technical summary of the changes.

---

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
2 New issues
0 Accepted issues

Measures
0 Security Hotspots
71.4% Coverage on New Code
0.0% Duplication on New Code

See analysis details on SonarQube Cloud