Abandoned datasets -- withdrawing

[ryscher]

See https://docs.google.com/document/d/1pGzPalpx_TO38DHqCmv7UgK7MmvP6kZdGmoBVAr9kHk/edit

• [ ] Set up final/withdrawn notifications for all datasets according to the schedule in the table
• [ ] When notifications indicate that the dataset is being withdrawn, also move it to withdrawn status