Fix plan deletion for plans who have had their uachieve schedule imported

[23langloisj]

❓Problem:
Whenever you create a plan and import your schedule from uacheive all the courses are added to the overriden section. Whenever you delete that plan and create a new one the courses stay in the overriden section. I believe it is not that we are not deleting the courses from the overriden section, but we never clear the selected pdf from the new plan modal upon actual creation of the plan.