.NET: Expose Executor Binding Metadata from Workflows

[kshyju]

Motivation and Context

As part of adding Durable support for workflows, we need access to executor binding metadata so that the Durable orchestration workflow runner can correctly route messages at runtime. The runner itself will be introduced in a follow-up PR from the corresponding feature branch.

Additional Context

The Python implementation already exposes executor binding information, whereas the .NET implementation does not. This PR closes that gap and brings feature parity between the two.

Description

This PR exposes executor binding information from a workflow, similar to the existing APIs that expose ports and edges.

public Dictionary<string, ExecutorBinding> ReflectExecutors()

This method allows callers to retrieve a copy of the executor bindings defined in a workflow.

Contribution Checklist

• The code builds clean without any errors or warnings
• The PR follows the Contribution Guidelines
• All unit tests pass, and I have added new tests where possible
• Is this a breaking change? If yes, add "[BREAKING]" prefix to the title of the PR.

[Copilot]

Pull request overview

This PR adds a new public method ReflectExecutors() to the Workflow class to expose executor binding metadata. This change brings the .NET implementation to feature parity with Python and enables the Durable orchestration workflow runner (to be introduced in a follow-up PR) to access executor binding information for message routing.

Changes:

• Added ReflectExecutors() method to expose executor bindings from workflows
• Returns a defensive copy of the executor bindings dictionary to prevent external modifications