Ability to move task and subtasks between them by drag and drop method

When we need to move a subtask to make it main task or vice a versa, then it should be possible to handle the same using drag and drop method. Also the email are getting placed in the Main task. From here it should be possible to drag and drop and position them in the respective subtask for which they are meant.

Yes, I would also like this - some subtasks might become full tasks