Add Injected Durable Client with Identity Based Connection Samples

[nytian]

Issue describing the changes in this PR

Add samples showing how to use external durable client with identity based connection.

Pull request checklist

• [ ] My changes do not require documentation changes
  • [ ] Otherwise: Documentation PR is ready to merge and referenced in pending_docs.md
• [ ] My changes should not be added to the release notes for the next release
  • [ ] Otherwise: I've added my notes to release_notes.md
• [ ] My changes do not need to be backported to a previous version
  • [ ] Otherwise: Backport tracked by issue/PR #issue_or_pr
• [ ] I have added all required tests (Unit tests, E2E tests)
• [ ] My changes do not require any extra work to be leveraged by OutOfProc SDKs
  • [ ] Otherwise: That work is being tracked here: #issue_or_pr_in_each_sdk
• [ ] My changes do not change the version of the WebJobs.Extensions.DurableTask package
  • [ ] Otherwise: major or minor version updates are reflected in /src/Worker.Extensions.DurableTask/AssemblyInfo.cs
• [ ] My changes do not add EventIds to our EventSource logs
  • [ ] Otherwise: Ensure the EventIds are within the supported range in our existing Windows infrastructure. You may validate this with a deployed app's telemetry. You may also extend the range by completing a PR such as this one.
• [ ] My changes should be added to v3.x branch.
  • [ ] Otherwise: This change only applies to Durable Functions v2.x and will not be merged to branch v3.x.