ToDoist Subtask improvements

[rsalsbery]

Currently, our system adds Subtasks when the Parent Task and Subtask meet the criteria of the filter you are using to display the list. The Parent Task Must be in the list from the filter in order for the Subtask to show. For example, you create a filter to find all tasks set to Priority 1. If both the Parent Task and the subtask meet this criteria, both will show on your list. If the Parent Task does not meet the criteria, neither task will show. If the Parent Task meets the criteria, but the Subtask does not, only the Parent Task will show.

This case is being made to see if we can improve upon this. Suggestions for improvements are below:

• A toggle to allow all Subtasks to show regardless of the criteria being set
• If a Subtask has a criteria set, and the Parent Task does not, both the Parent and Subtask will show in the filtered list

[Dan-Peck]

Once this is released, only when selecting a Project will there be a "hierarchical" display for Todoist tasks. All others will display in a "flat" listing. The sub-items were indeed being hidden due to their parents not also being a match to the filter. With the changes from this Issue, those will now properly show up in the listing.

[Dan-Peck]

Merged in @ 0998137 and added to the queue for upcoming release to the live site.