This is to achieve a clean separation of concerns - the watchdog is an inappropriate place for work management.
Also adds a WorkManager.RunInThreadPool() class which feeds through to Util.FireAndForget.
Also switches around the name and obj arguments to the new RunInThread() and RunJob() methods so that the callback obj comes after the callback as seen in the SDK and elsewhere
This is to reduce the potential for overload of the threadpool if there are many simultaneous requets in high concurrency situations.
Currently only applied to AvatarProperties and GenericMessage requests.
