Consider avoiding the use of powershell anti-pattern "return $foo"

As per:

https://github.com/Azure/azure-functions-powershell-worker/blob/v1.0.197/examples/durable/FunctionChainingApp/SayHello/run.ps1

While `return` accepts explicit retvals, it should only ever be used in naked form for exiting a function early. Returning a value is considered an anti-pattern in powershell because it gives the impression to people unfamiliar with the language that `return` is the only way to return values, when the reality is that any non-captured output is returned.

Start with examples/durable/FunctionChainingApp/SayHello/run.ps1, linked in the issue, and review how its output is produced in PowerShell. Done means the example no longer uses the cited return-value anti-pattern while preserving the function's output behavior.

Written by the indexing model from the issue text.