Impact of task workload being scheduled

Ask from dvd:
Make it easier to understand how much work you’re scheduling as a user. A summary confirmation dialog of how many miners and total duration of work would be helpful.

- Tasks are hard to grok, especially with symmetric loops
- Unclear how many miners are going to get scheduled a task, non-obvious to add more than one miner. No way to understand the amount of work being scheduled.
- Setting the duration and repeat scheduling is a bit confusing