Load a new task for users when reaching the done state

[fozziethebeat]

Right now in the task implementations we get to the end state and don't do anything useful. It would be better to cleanly reset the task, fetch a brand new task, and let the user keep contributing to the same task type.

This should affect everything under website/src/pages/create and website/src/pages/evaluate. Ideally this is some typescript library/hook that each of these pages can call to make sure everything is done correctly or a re-usable component that somehow handles it all.