Gantt Diagram shows tasks created with task macro

[KebabRonin]

Based on this comment, task macro tasks should not appear on the TaskManager livetable, as they are meant to be used as short, local to-do lists.

These tasks appear in the Gantt Diagram view, which makes it inconsistent with the LiveTable view. These tasks should be removed from showing up in the Gantt Diagram, and maybe add an option between the two behaviors, maybe as part of #80 .