[Durable] Add Version property to $Context

[AnatoliB]

Add Version property to the $Context object passed to orchestrator functions, matching the behavior implemented for .NET in-proc in Azure/azure-functions-durable-extension#3072.

As a result, PowerShell Functions users will be able to specify a version in host.json:

{
  "extensions": {
    "durableTask": {
      "defaultVersion": "2.0"
    }
  }
}

and check the orchestration version in their orchestrator functions in order to keep them backward compatible, for example:

if ($Context.Version -eq '1.0') {
    # Legacy code path
    Invoke-DurableActivity 'A'
} elseif ($Context.Version -eq '2.0') {
    # New code path
    Invoke-DurableActivity 'B'
}

Note: Microsoft.Azure.WebJobs.Extensions.DurableTask 3.1.0+ is required for this to work properly.

Pull request checklist

• My changes do not require documentation changes
  • Otherwise: Documentation issue linked to PR
• 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)

[AnatoliB]

I want to add an E2E test for this, but this will require an extension bundle with Microsoft.Azure.WebJobs.Extensions.DurableTask 3.1.0+, so we'll have to do it later. For now, I tested E2E manually.

[Copilot]

Pull Request Overview

This PR adds a Version property to the orchestration context, enabling PowerShell Functions users to access version information for backward compatibility.

• Introduces a lazy-loaded Version property in OrchestrationContext.
• Implements version extraction logic in OrchestrationVersionExtractor and extends HistoryEvent to support the Version field.
• Adds unit tests to validate the extracted version logic.

Reviewed Changes

Copilot reviewed 5 out of 5 changed files in this pull request and generated no comments.

Show a summary per file

File	Description
test/Unit/Durable/OrchestrationVersionExtractorTests.cs	Adds tests for various scenarios of version extraction.
src/DurableSDK/OrchestrationVersionExtractor.cs	Implements logic to extract the version from orchestration history events.
src/DurableSDK/OrchestrationContext.cs	Adds a lazy Version property that retrieves the version using the extractor.
src/DurableSDK/HistoryEvent.cs	Extends the HistoryEvent model to include the Version property.
release_notes.md	Updates release notes to document the new Version property.