Improved telemetry for worker initialization timeouts

[satvu]

It is difficult to pin down which methods or tasks are timing out during worker initialization. One example is that during a recent investigation, a timeout likely related to the wait between WorkerInitRequest and WorkerInitResponse bubbled up into a timeout error pointing at this line.

System.AggregateException : One or more errors occurred. (The operation has timed out.) ---> The operation has timed out.
    at System.Runtime.ExceptionServices.ExceptionDispatchInfo.Throw()
    at async Microsoft.Azure.WebJobs.Script.WorkerFunctionMetadataProvider.GetFunctionMetadataAsync(IEnumerable`1 workerConfigs,Boolean forceRefresh) at /src/azure-functions-host/src/WebJobs.Script/Host/WorkerFunctionMetadataProvider.cs : 115 ---> (Inner Exception #0) System.TimeoutException : The operation has timed out.
    at Microsoft.Azure.WebJobs.Script.Grpc.GrpcWorkerChannel.PendingItem.OnTimeout() at /src/azure-functions-host/src/WebJobs.Script.Grpc/Channel/GrpcWorkerChannel.cs : 1799
    at System.Runtime.ExceptionServices.ExceptionDispatchInfo.Throw()
    at async Microsoft.Azure.WebJobs.Script.Grpc.GrpcWorkerChannel.StartWorkerProcessAsync(CancellationToken cancellationToken) at /src/azure-functions-host/src/WebJobs.Script.Grpc/Channel/GrpcWorkerChannel.cs : 379<--- 

Potential next steps:

• Review of worker initialization timeout flows
• Review of the logging in this flow
• Design proposal needed for improvements