Optimize the integration of otel tracer

[ev1lQuark]

• The Dubbo-go kernel requires additional improvements to the configuration loading
  and component initialization for tracing. By enhancing these areas, applications can
  more easily and comprehensively control Dubbo-go's tracing capabilities through
  simple modifications to the configuration file.
• Currently, Dubbo-go only supports the propagator that adheres to the W3C standards
  for context propagation. Therefore, additional support for the B3 standard is required.
  To implement the B3 protocol, the implementation in opentelemetry-go-contrib can
  be used.
• The configuration of tracing needs to be further aligned with Dubbo-java to improve
  the observability of tracing. This can be achieved by adding support for configuration
  items such as sampling probability to achieve a more refined sampling strategy.
• In terms of observability backends, Dubbo-go currently only supports Jaeger, but it
  should also add support for other backends such as OTel and Zipkin. This would allow
  users to choose their preferred backend for tracing and enable Dubbo-go to integrate
  with various observability systems