TaskOrchestrationContext WaitForExternalEvent doesn't support overload without event data

[collinstevens]

unlike the in-process IDurableOrchestrationContext, the isolated TaskOrchestrationContext doesn't have a overload of WaitForExternalEvent which doesn't require event data.

the documentation shows this overload being used
https://github.com/MicrosoftDocs/azure-docs/blob/561b5b43606212719112cf3d6125af91241a6828/articles/azure-functions/durable/durable-functions-external-events.md?plain=1#L231-L245

the overloads on IDurableOrchestrationContext
https://github.com/Azure/azure-functions-durable-extension/blob/c7260c0a8b35bd35752615cae47c17db44f24798/src/WebJobs.Extensions.DurableTask/ContextInterfaces/IDurableOrchestrationContext.cs#L368-L393

more odd, the DurableTaskClient has an overload which indicates the event data may not be required for an event.

durabletask-dotnet/src/Client/Core/DurableTaskClient.cs

Lines 116 to 118 in b68c81c

	public virtual Task RaiseEventAsync(
	string instanceId, string eventName, CancellationToken cancellation)
	=> this.RaiseEventAsync(instanceId, eventName, null, cancellation);