[feat] Instructor-only attachments

[mdlama]

• [x] Add a new flag to attachments
• [x] Create a Public -> Registered -> Instructor Access Group
• [x] Set up admin interface to save/edit attachment access status
• [x] Set up controller/view for instructor-only files on submission
• [x] Allow HTML for group credentials and reasons
• [x] Remove Instructor Access Group migration script
• [x] Add two admin config inputs
  • Checkbox: Allow instructor-only attachments
  • Input: Instructors group (managers will manage membership)
• [x] Set up controller/view for instructor-only files on default view and bundle contents view
• [x] Set up view to allow user to ask for instructor-only access
• [x] Refactor bundle code to create two bundles: one with and one without instructor materials
• [x] Create migration script to recreate bundles (make sure bundles get recreated on pub edit)
• [ ] Ask when user filling out profile for first time (or if editing)

What do we want to ask for as “proof”? Suggestions:

• Professional website
• LinkedIn profile
• Department website

Use viewlevels and usergroups tables Might want a way to tag or mark a publication to let users know there are instructor materials