feat(jans-auth-server): Add structured logging with OpenTelemetry integration for enhanced observability

@yuriyz is already working on this.

Since Nov 11, 2025.

### Description

Enhance the jans-auth-server logging capabilities by implementing structured logging with OpenTelemetry integration. This will enable better observability, debugging, and monitoring of authentication flows in production environments.

### Development target issue

Implement comprehensive structured logging throughout jans-auth-server with OpenTelemetry (OTel) support to enable distributed tracing and better observability.

### Tasks

- [ ] Replace current logging framework with structured logging (JSON format)
- [ ] Add correlation IDs to track requests across microservices
- [ ] Implement OpenTelemetry SDK integration for traces and spans
- [ ] Add configurable log levels per component (auth, token, userinfo, etc.)
- [ ] Create span annotations for key authentication events (login attempts, token generation, consent flows)
- [ ] Add metrics export capabilities (Prometheus format)
- [ ] Implement log sampling for high-volume production environments
- [ ] Add documentation for configuring log exporters (OTLP, Jaeger, Zipkin)
- [ ] Create example configurations for common observability platforms (Datadog, New Relic, Elastic APM)
- [ ] Add performance tests to ensure minimal overhead

### Benefits

- **Better Debugging**: Structured logs with correlation IDs make it easier to trace authentication flows
- **Production Monitoring**: Real-time insights into system behavior and performance
- **Compliance**: Detailed audit trails for security and compliance requirements
- **Performance Analysis**: Identify bottlenecks in authentication flows
- **Integration**: Works with modern observability platforms out of the box