Add k8s.{pod,node}.network.{io,errors} metrics

[ChrsMark]

Part of https://github.com/open-telemetry/semantic-conventions/issues/1032

Changes

This PR adds the following metrics:

• k8s.pod.network.io
• k8s.pod.network.errors
• k8s.node.network.io
• k8s.node.network.errors

The above metrics are already used in the Collector in the kubeletstats receiver and the naming is aligned with the System metrics.

These metrics come with the following attributes network.io.direction and system.device which are already part of SemConv registry and are used in the System metrics. The attributes in the Collector will need to be adjusted to follow the recent SemConv rules.

Merge requirement checklist

• [x] CONTRIBUTING.md guidelines followed.
• [x] Change log entry added, according to the guidelines in When to add a changelog entry.
  • If your PR does not need a change log, start the PR title with [chore]
• [ ] schema-next.yaml updated with changes to existing conventions.