Easier subtask re-ordering

There are 3 key things missing that makes it difficult to re-order/move/manage subtasks:

  1. Ability to re-order subtasks from List View, instead of having to open the Details sidebar

  2. Ability to drag tasks outside of main task and convert them into a main task from List View*.

(*You can do this by grabbing & dragging the subtask from the Details sidebar, but you should be able to it right from List View)

  1. Show at least 2 levels of subtasks in List View