Undo "working on it" to move task out of work list

[#1]

Description - There used to be functionality in an older version of Home to revert a task back to not working on it in what is now the My Work widget. 

Why is this feature important to you - Occasionally we need to backtrack the timeline to a previous task for an edit before creative can be reviewed again. However, if the reviewer hit working on it, the task still shows up in their work list since we currently have all users with working on and ready to start filters turned on.

How would you like the feature to work - Have a "not working on it" button for the task to get it out of the work list when not ready for them to review. 

Current Behaviour - If a user hits work on it, the task remains in their work list even if the task is no longer ready for them due to the prior task being backtracked.