[enhancement]: Add Logic to the Functions App Task to detect and set FUNCTIONS_WORKER_RUNTIME correctly.

[FinVamp1]

Task name

AzureFunctionApp@2

Describe your feature request here

Following on from microsoft/durabletask-dotnet#160 where the DevOps Task doesn't set FUNCTIONS_WORKER_RUNTIME for apps.

[JayAtSherweb]

Any update?

[FinVamp1]

Triaged and assigned priority