[TRUNK-6521] Add contract verification test for PersonService.getPersonByUuid

[MonotonousHarsh]

JIRA Ticket

https://issues.openmrs.org/browse/TRUNK-6521

Description

The Issue:
The PersonService contract implies that querying getPersonByUuid with a non-existent UUID should return null. However, PersonServiceTest currently lacks a test case to enforce this "sad path" behavior.

Risk:
Without this coverage, a future regression could cause the service to throw an unhandled exception (e.g., ObjectNotFoundException) instead of returning null, potentially breaking downstream modules that expect a null check.

My Solution:

• Added getPersonByUuid_shouldReturnNullIfNoPersonFoundWithUuid to PersonServiceTest.java.
• Verifies that the API handles invalid UUIDs gracefully by returning null rather than crashing.

Dev Checklist

• Added unit tests for new functionality
• Ran mvn test -Dtest=PersonServiceTest (147 tests passed)

[sonarqubecloud]

Quality Gate passed

Issues
0 New issues
0 Accepted issues

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

See analysis details on SonarQube Cloud