Add FAFSA Not Applicable to Participants

You might see that the two first commits cancel each other out (except the first one adds the migration to add the boolean field fafsa_not_applicable to participants). The third is the correct one which adds the functionality. I'm still trying to get the hang of properly using version control, but I made some simple edits to the view stubs for the edit form and the _paperwork_status. Let's see what happens, and we can always revert if necessary.