[feat]: add resource labels attribs as span tags and use service.name

[ericmustin]

This PR Adds the Resource labels as span tags, and also uses the more canonical resource service.name to set the span's service when it exists.

This work brings us closer to the spec of how OTEL service naming should work, and it's a pattern that's been addressed in other vendor/backend specific exporters

• https://github.com/open-telemetry/opentelemetry-specification/blob/master/specification/resource/semantic_conventions/README.md#service
• Use resource service.name as zipkin service name open-telemetry/opentelemetry-js#919
• Use resource label service.name as Jaeger service name open-telemetry/opentelemetry-java#978

Work following this will be to ensure our documentation is appropriate for onboarding as well