[MJ-166] navigation - account pages requiring activation still accessible

Adds user_passes_test decorators on views to check if user is disabled/active as well as a notification on the main page indicating that a user's account is inactive. If user does not have permissions for a view, they are redirected to the main page.

This is pretty simple to manage with the permissions we have but once we define more complex levels of permissions for job seekers and employers, we might consider using the Django group and permission models.

All tests pass.