Add robust OpenTelemetry configuration and instrumentation

[asafchen-dig]

This PR implements robust OpenTelemetry configuration with fallbacks and error handling. The changes include:

1. Updated application.properties with explicit OTel configuration
2. Added OtelConfig class with proper error handling and fallbacks
3. Implemented health check indicator for OTel status monitoring
4. Added custom instrumentation utilities for easier tracing

Key features:

• Environment variable fallbacks for all configurations
• Graceful degradation to no-op implementation on errors
• Health monitoring through Spring Actuator
• Utility methods for common instrumentation tasks

The implementation follows best practices for OpenTelemetry integration in Spring Boot applications while maintaining backward compatibility.