chore: enhance Kafka health check

[gibaros]

Enhance Kafka health check with comprehensive isHealthy method (#4318)

• Replace Consumer.allConnected() with consumer.isHealthy() for more comprehensive health checks
• The isHealthy() method checks: connection status, partition assignments, poll health, and topic metadata
• Aligns with ml-api-adapter PR Bump npm-check-updates from 4.0.2 to 4.0.3 central-ledger#619 pattern for Kafka-aware health endpoints
• Update unit tests to mock getConsumer and isHealthy methods

Refs: mojaloop/project#4318

[sonarqubecloud]

Quality Gate passed

Issues
0 New issues
0 Accepted issues

Measures
0 Security Hotspots
0.0% Coverage on New Code
1.0% Duplication on New Code

See analysis details on SonarQube Cloud