Add a timeout when polling for new blobs (from CRI)

[hossam-nasr]

Timebox polling for new blobs when using storage blob triggers, and throw a timeout error when the timeout is exceeded.

This would be something like this:

public static async Task<TResult> WithTimeout<TResult>(this Task<TResult> task, TimeSpan timeout)
{
    if (task == await Task.WhenAny(task, Task.Delay(timeout)))
    {
        return await task;
    }
    throw new TimeoutException();
}

And change ExecuteAsync here to use WithTimeout when polling for new blobs. When the TimeoutException is thrown, we can signal a restart for the listener, or even the whole Function host.

This issue was surfaced by a CRI, in which the SDK stopped polling for new blobs without throwing any exception or error. We couldn't find the exact cause of the issue, but it wasn't mitigated until the customer restarted the function app.