Sub-orchestrations in PowerShell Durable Functions

Sub-orchestrations are not yet supported in PowerShell according to the [documentation](https://learn.microsoft.com/en-us/azure/azure-functions/durable/durable-functions-sub-orchestrations). I have a use case where this would be extremely useful. Is this functionality on the roadmap?

Start with the linked Azure Durable Functions sub-orchestrations documentation and compare its stated support with the PowerShell worker. The issue asks whether this functionality is on the roadmap, so done would require a maintainer decision or roadmap update rather than a self-contained change.

Written by the indexing model from the issue text.