Support having a "handle" field for the RetryOptions object

[davidmrdavid]

In retriable DF APIs, dotnet users can add a "handle" field to their "RetryOptions" object. This allows them to provide custom logic to determine whether or not to shortcircuit a retriable operation such that the task is no longer attempted. This is difficult to do in the OOProc model, but we should investigate how to enable it.

Some of the relevant dotnet documentation is here: https://docs.microsoft.com/en-us/dotnet/api/microsoft.azure.webjobs.extensions.durabletask.retryoptions?view=azure-dotnet