Add k8s container resource related metrics

[ChrsMark]

1st part of https://github.com/open-telemetry/semantic-conventions/issues/2074

Changes

This PR adds k8s container resource related metrics that are already in use by the Opentelemetry Collector.

Related to https://github.com/open-telemetry/semantic-conventions/issues/1032

I suggest to change the cpu_limit to cpu.limit since it makes sense to have a common k8s.container.cpu. namespace.

The following metrics are added:

Old (Collector)	New
k8s.container.cpu_limit	k8s.container.cpu.limit
k8s.container.cpu_request	k8s.container.cpu.request
k8s.container.memory_limit	k8s.container.memory.limit
k8s.container.memory_request	k8s.container.memory.request
k8s.container.storage_limit	k8s.container.storage.limit
k8s.container.storage_request	k8s.container.storage.request
k8s.container.ephemeralstorage_limit	k8s.container.ephemeral_storage.limit
k8s.container.ephemeralstorage_request	k8s.container.ephemeral_storage.request

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.