add support for grpc exporting of metrics etc

[iamKunalGupta]

Some notes:

• There is a go.opentelemetry.io/contrib/exporters/autoexport package which might help follow best practices for otlp to read the right environment variables and setup configuration.
  • Even if it does not support everything, follow: the priority https://opentelemetry.io/docs/languages/sdk-configuration/otlp-exporter/#otel_exporter_otlp_protocol if possible