New overloads for WriteStringAsync and WriteBytesAsync method which takes CancellationToken#1111

kshyju merged 3 commits intomainAzure/azure-functions-dotnet-worker:mainfrom

shkr/gh1078_writeasync_with_cancellation_tokenAzure/azure-functions-dotnet-worker:shkr/gh1078_writeasync_with_cancellation_tokenCopy head branch name to clipboard