Planner Checklist item additions:

1) Provide the ability to assign one or more people to Planner checklist items within a card.
(The card itself has assigned people but each Planner checklist item should also have assigned people.)

2) Provide the ability to assign due dates to Planner Checklist items within a card.
(The card itself has a due date but each Planner checklist item should also have their own due dates)