Various improvements to UK2Node_BaseAsyncTask:
- Moved node enumeration from the menu builder into the node
- Added the latent icon to the corner of the node
- Added optional support for a separate Activate call on the proxy object, allowing immediate success/failure instead of having to delay it a frame
- Added default behavior for category and node title, pulling it from the factory function
[CL 2049507 by Michael Noland in Main branch]