feat: Add NebulaAdapter integration for enhanced API call logging

[AndyHaas]

• Add NebulaAdapter class with optional Nebula framework integration

  • Graceful degradation to System.debug when Nebula not available
  • Support for both managed (namespaced) and unlocked packages
  • HTTP request/response logging with customizable headers
  • Record association for traceability
  • Error logging with exception details

• Enhance RestLib with logging context support

  • Add makeApiCall overload with relatedRecord parameter
  • Integrate NebulaAdapter for automatic request/response logging
  • Maintain backward compatibility with existing methods

• Extend RestClientLib with logging-enabled method overloads

  • Add relatedRecord parameter to all HTTP methods (get, post, put, patch, del)
  • Support for 2-param, 3-param, and 4-param method combinations
  • Consistent API design across all convenience methods

• Update RestClient static methods

  • Add makeApiCall overload with relatedRecord parameter
  • Maintain backward compatibility with existing static calls

• Enhance AsyncRestClient for background logging

  • Add constructor overload with relatedRecord parameter
  • Pass logging context through to API calls
  • Support for both sync and async logging scenarios

• Add comprehensive test coverage

  • Create NebulaAdapter_Test class with HTTP mock testing
  • Test both Nebula available and fallback scenarios
  • Validate request/response logging functionality
  • Test record association and error handling

• Update package manifest and documentation

  • Add NebulaAdapter and test classes to package.xml
  • Update README with complete NebulaAdapter documentation
  • Add API reference for all new logging methods
  • Document usage examples and best practices

• Zero external dependencies

  • No compilation dependencies on Nebula
  • Safe deployment to any Salesforce org
  • Optional enhancement that doesn't break existing functionality