Remove Dead Code: PermissionsController confirm and copy methods and associated view
Hyrax::PermissionsController looks to have some code from the early days of FileSets inheriting their Work's permissions settings. These are the confirm() and copy() methods.
aside: In the current version of Hyrax the superseding confirm_access() and copy_access() methods form the basis of the "Confirm Access" (code/route) or "Apply Changes to Contents?" (label) screen.

Leaving the unused methods in place makes this controller confusing. Though it was partially cleaned up in #4650, I would like to remove the rest of it.
The reason for this dead code/duplication seems to go back to when automatic visibility and user permissions were being applied to FileSets in Curation Concerns and Sufia, with both paths making it into Hyrax: https://github.com/samvera-deprecated/sufia/commit/2159aa70b66500383f94e14f762b68a403fa8891 https://github.com/samvera-deprecated/sufia/commit/2f100a6965c5f20963cb070362286a888261b438
The remaining dead code is here (assuming the deprecated method can be removed also... not sure what benefit it can have if it was only ever used in a contrived spec in Hyrax): https://github.com/samvera/hyrax/blob/479a2b95182c7de7dd5933ed020d9cd00f93c6e1/config/routes.rb#L204-L205 https://github.com/samvera/hyrax/blob/479a2b95182c7de7dd5933ed020d9cd00f93c6e1/app/controllers/hyrax/permissions_controller.rb#L9-L19 https://github.com/samvera/hyrax/blob/479a2b95182c7de7dd5933ed020d9cd00f93c6e1/app/views/hyrax/permissions/confirm.html.erb#L1-L15