We have found ourselves in the need of specifying maxRetries and backoff globally on a queue basis, similar to how you can do it on Google Cloud Tasks. It makes it more convenient to have these parameters listed in a single place (most likely a config file) than having to implement them in every job and then trying to keep them in sync.

I used a similar approach as it was done in #139 with handler url.
Initially I wanted to use the callback inside getWorkerOptions() of TaskHandler, but that method has not job or task context to get the queue from. Adding IncomingTask argument to the method would introduce a breaking change in case someone has extended `TaskHandler.