fix: duplicate metrics pushed via otel sdk

[iamKunalGupta]

This is accomplished by clearing out the metric from the MetricsMap once Observed/Collected.

Use a query like:

max(peerdb_cdc_slot_lag_MB{}) without(k8s_pod_name, k8s_pod_uid, k8s_pod_ip, k8s_pod_start_time, k8s_node_name)

to deduplicate metrics across pods, they are only pushed once in 1 cycle in a pod

TODO:

• [ ] Enable GRPC exporter
• [ ] Update dockerfile env vars:
  • [ ] Set a default export interval (?? in the docker file ??)
  • [ ] Set default compression
• [ ] Revert cron back to 5 minutes
• [ ] Open replication connections