exporter/datadogexporter: use pkg/trace

[gbbr]

Description:

This change make use of the exact same code that the Datadog Agent uses for processing traces. A module was created in the Datadog Agent repository that is now imported here: github.com/DataDog/datadog-agent/pkg/trace.

This change should allow for more consistent and stable behaviour.

Testing:

All unit tests were kept. Removed functionality was moved to the pkg/trace module as part of DataDog/datadog-agent#11548.

Documentation:

Attributes are mapped to Datadog container tags internally as follows (considering the left side OTLP attributes are set in the SDKs):

             container.id -> container_id
           container.name -> container_name
     container.image.name -> image_name
      container.image.tag -> image_tag
       k8s.container.name -> kube_container_name
         k8s.cluster.name -> kube_cluster_name
      k8s.deployment.name -> kube_deployment
      k8s.replicaset.name -> kube_replica_set
     k8s.statefulset.name -> kube_stateful_set
       k8s.daemonset.name -> kube_daemon_set
             k8s.job.name -> kube_job
         k8s.cronjob.name -> kube_cronjob
       k8s.namespace.name -> kube_namespace
             k8s.pod.name -> pod_name
           cloud.provider -> cloud_provider
             cloud.region -> region
  cloud.availability_zone -> zone
      aws.ecs.task.family -> task_family
         aws.ecs.task.arn -> task_arn
      aws.ecs.cluster.arn -> ecs_cluster_name
    aws.ecs.task.revision -> task_version
    aws.ecs.container.arn -> ecs_container_name

[mx-psi]

I did a first pass on this and left a lot of comments, some of them because I don't understand the logic of the APM side as well as I would like 😅

This is a huge PR and I would prefer to the extent that it is possible to focus it exclusively only on changes that relate to swapping the current logic by pkg/trace and leave everything else out; the other changes make sense but we can leave them for a different PR

I think it is also very important to document the changes in behavior from the current logic to the one that we are adding. I would suggest adding this as a 'breaking change' in the changelog and list down important details in the logic that will change after the swap is complete.

[github-actions]

This PR was marked stale due to lack of activity. It will be closed in 14 days.